Closed Bank Account

I had an Premium account with FNB and I realized that charges were more and this I decided to close off the account, i went to the branch in Fourways Mall, I was told that I need to talk to my private banker, and I told ask the consultant lady that was helping me that who was my private banker, she was unable to tell me. I told her that I don't need the account anymore because I am not working anymore. I left the destroyed card at the bank, now I receive msgs from fnb that my account is overdraft, and I noticed that all my sassa relief fund were paid in the fnb account, so fnb is now helping themselves with my relief money from sassa. They already took R1050.00.