MTN has billed me R16k on a WRONG CONTRACT!!!

I purchased the Sony M4 Aqua from MTN Stoneridge on my sisters account. The package was for R189.00.<br> The paperwork issue by Tshepiso was correct and we signed into the contract. MTN Head Office put me onto the wrong contract. Trying to resolve this issue has taken 3 months already with very little progress. <br> <br> The most recent communication i have received was an sms below which as a result is affecting my sisters credit.<br> <br> \Yello, overdue account warning. Please Pay R16073.36 to avoid service suspension. Make payment to ABSA Bank, account no. ***. Kind Regards, MTNSA\"<br> <br> PLEASE DROP THESE INCURRED CHARGES AS A RESULT OF MTN PUTTING ME ONTO THE INCORRECT CONTRACT. <br> <br> Should this matter persist I will take MTN to court as I am well within my part of the contract both Ms T Pillay and I have signed into. <br> I will remind MTN that this is a direct violation of my consumer rights and a direct breach of contract. All evidence to prove the consumer and retail store representative are innocent have been sent to MTN.<br> <br> It is clear that MTN does not think this is a serious enough situation. Ive tried every avenue to resolve this situation and nothing seems to work. <br> <br> Admin Email ***"