Debit on a closed account

I paid off my credit card account, was told it would be closed, standard bank continues to debit for a paid up supposedly closed account, I have been trying to get my refund been promised to will come through on a certain day but nothing, I phone to inquire I was put on hold for 34 minutes how rediculos. Till now I have not received my refund nor do I have an answer as to what the delay is