Bad service. Clear my name from MTN.

My Name is Nobulali Tofi

I opened the account with you Mondo on the 30th of March MTNcontact deal I Phone 6+ The phone was delivered on the 6th of march, t was 1 day after receiving the phone . the phone was not working only showing the iPhone logo not switching on, I returned it to OR Tambo airport where they gave me the IRM number that I provided to the customer service to track the phone. They tracked the phone and gave me the ref number RCO212224 The person who called me and assisted me with this cancelation was Dhanesh. Now MTN says I need to pay R8327.86 FOR A PHONE THAT I DO NOT HAVE. When I spoke to Dhanesh he said everything was cancelled even the debit order and I can apply again for a new phone.Now my credit score had gone down by 15 points because this is added on my accounts and O don't have the phone they received it back and I can't apply for another phone. Fix this mass and give me a new phone that is working for messing up my profile. Regards Nobulali