Disappointed client

Good day I had contract with cell C that I terminated last year in October. When I spoke to a cell C consultant I requested that my account be closed, and according to the consultant the payment indicated that the last payment will be on the 1st of November 2021, to my surprise on the 1st of December they debited of which the amount I reversed and called them immediately, enquiring why the debit because the contract was terminated. The consultant who was assisting me at the time said she will listen to the recording and come back to me, instead a month later I was called by one of the MBD attorneys that my account has been handed over to them. I was requested by the attorneys that I pay the amount which included the legal fees. I paid the amount in fear of being blacklisted and emailed proof of payment to the MBD attorneys. I have never received any response from the attorneys and the account is still active and owing the same amount that I apparently owed according to them. I'm not happy with the service I received from Cell C and MBD attorneys. No communication is done, no confirmation of receipt of payment and why the account is not yet closed as its paid in full.