diff --git a/bot/modules/accountability/TimeSlot.py b/bot/modules/accountability/TimeSlot.py
index e2c7b44b..fb0f4551 100644
--- a/bot/modules/accountability/TimeSlot.py
+++ b/bot/modules/accountability/TimeSlot.py
@@ -37,7 +37,7 @@ class SlotMember:
 
     @property
     def member(self):
-        return self.guild.get_member(self.data.userid)
+        return self.guild.get_member(self.userid)
 
     @property
     def has_attended(self):
@@ -254,6 +254,11 @@ class TimeSlot:
         Adds the TimeSlot to cache.
         Returns the (channelid, messageid).
         """
+        # Cleanup any non-existent members
+        for memid, mem in list(self.members.items()):
+            if not mem.data or not mem.member:
+                self.members.pop(memid)
+
         # Calculate overwrites
         overwrites = {
             mem.member: self._member_overwrite
diff --git a/bot/modules/accountability/commands.py b/bot/modules/accountability/commands.py
index dd9bc796..551ddc15 100644
--- a/bot/modules/accountability/commands.py
+++ b/bot/modules/accountability/commands.py
@@ -11,8 +11,9 @@ from data.conditions import GEQ
 from .module import module
 from .lib import utc_now
 from .tracker import AccountabilityGuild as AGuild
+from .tracker import room_lock
 from .TimeSlot import SlotMember
-from .data import accountability_members, accountability_member_info, accountability_open_slots, accountability_rooms
+from .data import accountability_members, accountability_member_info, accountability_rooms
 
 
 @module.cmd(
@@ -104,29 +105,30 @@ async def cmd_rooms(ctx):
         cost = len(to_cancel) * ctx.guild_settings.accountability_price.value
 
         slotids = [row['slotid'] for row in to_cancel]
-        accountability_members.delete_where(
-            userid=ctx.author.id,
-            slotid=slotids
-        )
+        async with room_lock:
+            accountability_members.delete_where(
+                userid=ctx.author.id,
+                slotid=slotids
+            )
 
-        # Handle case where the slot has already opened
-        for row in to_cancel:
-            aguild = AGuild.cache.get(row['guildid'], None)
-            if aguild:
-                if aguild.upcoming_slot and aguild.upcoming_slot.data and (aguild.upcoming_slot.data.slotid in slotids):
-                    aguild.upcoming_slot.members.pop(ctx.author.id, None)
-                    if aguild.upcoming_slot.channel:
-                        try:
-                            await aguild.upcoming_slot.channel.set_permissions(
-                                ctx.author,
-                                overwrite=None
-                            )
-                        except discord.HTTPException:
-                            pass
-                    await aguild.upcoming_slot.update_status()
-                    break
+            # Handle case where the slot has already opened
+            for row in to_cancel:
+                aguild = AGuild.cache.get(row['guildid'], None)
+                if aguild and aguild.upcoming_slot and aguild.upcoming_slot.data:
+                    if aguild.upcoming_slot.data.slotid in slotids:
+                        aguild.upcoming_slot.members.pop(ctx.author.id, None)
+                        if aguild.upcoming_slot.channel:
+                            try:
+                                await aguild.upcoming_slot.channel.set_permissions(
+                                    ctx.author,
+                                    overwrite=None
+                                )
+                            except discord.HTTPException:
+                                pass
+                        await aguild.upcoming_slot.update_status()
+                        break
 
-        ctx.alion.addCoins(-cost)
+        ctx.alion.addCoins(cost)
         await ctx.embed_reply(
             "Successfully canceled your bookings."
         )
diff --git a/bot/modules/accountability/tracker.py b/bot/modules/accountability/tracker.py
index 6a5c2799..19ccb663 100644
--- a/bot/modules/accountability/tracker.py
+++ b/bot/modules/accountability/tracker.py
@@ -19,6 +19,19 @@ from .module import module
 
 
 voice_ignore_lock = asyncio.Lock()
+room_lock = asyncio.Lock()
+
+
+def locker(lock):
+    """
+    Function decorator to wrap the function in a provided Lock
+    """
+    def decorator(func):
+        async def wrapped(*args, **kwargs):
+            async with lock:
+                return await func(*args, **kwargs)
+        return wrapped
+    return decorator
 
 
 class AccountabilityGuild:
@@ -184,7 +197,7 @@ async def turnover():
             )
             for slot in current_slots
             for mem in slot.members.values()
-            if mem.member.voice and mem.member.voice.channel != slot.channel
+            if mem.data and mem.member and mem.member.voice and mem.member.voice.channel != slot.channel
         )
         # We return exceptions here to ignore any permission issues that occur with moving members.
         # It's also possible (likely) that members will move while we are moving other members
@@ -279,7 +292,8 @@ async def _accountability_loop():
             next_time = next_time + datetime.timedelta(minutes=5)
             # Open next sessions
             try:
-                await open_next(next_time)
+                async with room_lock:
+                    await open_next(next_time)
             except Exception:
                 # Unknown exception. Catch it so the loop doesn't die.
                 client.log(
@@ -293,7 +307,8 @@ async def _accountability_loop():
         elif next_time.minute == 0:
             # Start new sessions
             try:
-                await turnover()
+                async with room_lock:
+                    await turnover()
             except Exception:
                 # Unknown exception. Catch it so the loop doesn't die.
                 client.log(