Holding my number hostage so I cannot port out

I am literally receiving the worst service ever from Telkom. I am trying to port my number from Telkom to MTN, but Telkom is literally holding my number hostage. I discovered over the weekend that I have an outstanding balance of R0.49 from a contract that I had canceled years ago. I made the payment of R0. 49 and have been advised that the payment is reflecting, however they are still not releasing my number. I have called the call centre numerous times and no one is willing to assist. I keep failing the security questions because I cannot tell them when my debit order date is. I DO NOT HAVE A DEBIT ORDER DATE as I do not have a contract with them and cannot remember from years ago. I have asked to speak to a manager but they are never available. I ws promised a call back from a manager and that hasn't happened either. The store tells me I need to contact the call centre and the call centre tells me I need to go to the store. I'm then told I need to speak to MTN and MTN tells me Telkom needs to release my number. I'm at my wits end with Telkom. Their service is literally the worst.