Poor service

Am writing again about standard bank their service suck they dont know how to do their job its 3 months now i keep on calling them and going to their branch but they cant resolve the issue. Had a personal loan with them have settle the amount but everymonth on the 25th they keep on debiting but they gave me a letter confirming that the account its closed but still they debit they are inconveniencing me as the customer. Please guys do your job if i was not monitoring my account which means was going to loss my money just like that.