Cell C Pathetic Service

I am a contract customer with Cell C. Due to financial changes, I decided to pay up my contract in full as of 28 June 2018. I contacted their retentions department and requested that they terminate my contract as of 00h00 on 1 July and port my number to pay as you go / Prepaid. the call centre agent telephonically agreed to process the change over as discussed. Half an hour later after this call, i received an sms stating that my line was already changed to prepaid. I have lost over 90 minutes which were paid for and now Cell c cannot refund me my paid for minutes that had. This is theft!