refusing to refund what's due to me.

I had a contract with MTN and settled it , kept the same number as pre-paid , as a result the was an amount that was due to me about ZAR1090 , that was confirmed by both MTN contact centre agent and MTN store. I forwarded my request to MTN refunds/collections on the 02 December 2023 with all required documents and received a response stating refunds will take up to 14working days , 14days later an email came from MTN retention to say they unable to retrieve my profile. I responded to retentions and never received any feedback whatsoever. MTN complaints was always copied on all emails, however no intervention from them.