Debit order on closed account

African bank is the worsed bank ever, I called them to try n make arrangement to pay up all my account because I am going through financial difficulties, they declined my offer to settle even thou that would mean that they got their contractual amount which includes interest. I decided to settle their cridit card, this morning, they came into my account n debited for the closed credit card, please explain how am I supposed to pay other debt when I settled u n u still debit