The worst service I've ever received

I had two contracts running with MTN, the 24 month period lapsed and I did not want to upgrade and I carried on a month to month. I was out of contract. I paid monthly via EFT and things were fine.<br> <br> One month I payed but put in the wrong reference number for the payment, I was missing a digit. I realised this when my account was suspended. Now trying to call MTN on a suspended line what they do is automatically redirect you to some pre-recorded message and you will not get entertained nor given the platform to explain the issue. I sent an e-mail to an mtn e-mail address I was once helped by when I had a similar incident a couple of months before. Eventually I went to a store and showed them the proof of payment and they got my lines unblocked.As soon as this happened I phoned the call centre and told them I wanted to end my month to month with immediate effect as my wife was heavily pregnant at the time and I had to be able to use my phone.Six months after this cancellation MTN is sending debt collectors saying I owe R1200 and no-one is able to explain why even though the consultants can see that I was out of contract and cancelled this.<br> Legal department is not answering mails.