Missed payment on closed account

I have a matter of serious concern. I registered here as a result of this situation. I moved out of Leo's Place 3 months ago and my account is supposed to be closed by now. I keep getting invoices from the finance team which doesn't make sense since I no longer stay there and my account is supposed to have been closed long time ago. I paid the R16 last month which I wasn't even supposed to pay. I received a notification from the credit Bureau that I missed my last month's rent which baffles me since I no longer stay there and I had paid everything I owed and already received my security deposit. This is causing grave impact on my credit profile as my score dropped by 10 points as a result of the "so called" missed payment. I received another invoice for this month again. Whoever is not doing their job at finance needs to update my account and close it. This can no longer continue as I'm already impacted negatively. I'm asking that someone responsible for this resolve this issue immediately.