********** upgrade on my contract number

I made a payment in February 2015 at Mtn canalwalk branch in capetown and queried my upgrade illegibility. The shop assistant inform me that an upgrade was done on my contract number and that i was only due for the upgrade in 2017. This upgrade was done on 29 January 2015 according to the record on their system. Also the assistant told me that this upgrade was done in Gautang but he could not give me information nor details of the contract description. He also then said that i should get an affidavit at the police station and send to mtn stating that i was not the person responsible for the upgrade. I reported this incident telephonically and had not have response from mtn. On the 02 July 2015 I send all these documents to Kim Swanepoel at Mtn and she told me that I would have a response within 7 -10 days since then I did not hear from her. Today I phoned again and I was asked to send my documents through because there was a reply to Kim Swanepoel on 3 July 2015 that my certify copy of my ID was not readable. I resend these documents to Sibongile Libazi where she confirmed that there was nothing wrong with my documents. Why is this issue still not resolved,i'm not paying this acc