Payment not reflecting - line will be suspended

I have 3 lines with mtn which I have made 3 separate payments for on the 30/06/15 which I normally do every month for 8 years that I have been with mtn. 1 payment is not reflecting on my statement and I have received sms's stating that my line will be suspended. I have tried contacting the call centre to sort this out but it is impossible to get a hold of anyone. I went as far as emailing everyone that works for mtn that is on my mailing list. Only to get a reply a day later stating that the suspension has been lifted however I am still receiving sms's stating my account is in arrears. I then get another email stating that the payment that was not reflecting was made to iTalk celluar (btw which is part of MTN) and I must request a refund. I have been making this payment to iTalk for the pass 8 years. My 2nd line is due for an upgrade however I cannot upgrade as my account is still showing in arrears on your system. I am really considering migrating to another cellular network as MTN is just becoming a huge inconvenience in my life!!!