Refund my money and close my account

i have a credit card with African bank that was handed over to nimble which was in arears, i was getting calls from both Nimble and AFRICAN BANK which i don't know why was African bank still calling me or debiting my account if they handed over my account, on the 5th of august 2025 i made a payment to Nimble group as they said my account has a discount if i settle it i paid R6964,on the 18 of August i went to African bank branch to inform that may the debit order not go through as i have settle my account and i do have proof of payment but i was place on the phone for 1hour talking to different agents and i was asked to send proof of your i did that, on the 20th the debit order went off my account African bank debited R598.71 but i have settled the account and gave them proof of payment now they telling i need to deal with Nimble but they are once that handed over my account while they were still debiting my account. Yesterday i called nimble and they told me they waiting for African bank to close and issue a paid-up request was sent on the 18th but no response from them, my biggest issue is they not refunding my money they debited