Bad experience with MRPmobile

I had a MRPmobile account which I'm under the impression that it was paid off in February 2018. My monthly debit order was R299 and the last one was paid in February 2018. I have not heard any calls from this company before informing me of any outstanding payments till I got a call from a collection agency saying I'm owing R5 300 on this account. Subsequent to that I checked my credit report and the amount is listed on the credit bureaus. The collection agency has no detail of how the R5 300 is made up and MRPmobile also tells me that they have no record of my account. They cannot give me any information, so I have this listing and the companies concerned cannot help me. I have called MRPmobile numerous times and it's either they send me from pillar to post transferring calls to everyone who cannot assist or they cut the call on my ear. I'm now waiting on the credit ombudsman and Icasa for a way forward.