Billing Case handed over without resolution

Following my previous case reported on 16.12.2014 on billing and refusal to investigate, I went to MTN Roodeport, Johannesburg to further explain my case and request an investigation. I was assisted by an administrator named Andre Bowden. Andre escalated my query to obudsman by the name bnaidoo. To this date I have not received feedback from anyone even after numerous follow ups. To my surprise I received an sms on 20.07.2015 from MBD INC notifying me that MTN had handed me over for debt collection of amount now R18,669.40 from R9,453.9? and mean while I am waiting for feedback from MTN? I called MBD INC to explain the matter and was advised by Tina Naidoo, call centre consultant that they only deal with collection and I would have to go back to MTN. At this point I feel I am being unfairly treated as customer, being tossed around without any feedback on my investigation. At this point I feel exposed to the risk of my clean credit record getting messed up. Can someone please investigate this case and help me. MTN is not attending to my query with the urgency requested and now I am having to deal with debt collectors... extremely disappointed and unfairly treated.