Terrible and Poor Service

On the 31 October 2018 I posted on hello peter regarding the bad service I am receiving from MTN for a device that I toke out on contract and returned within 10days. It was confirmed that the contract was cancelled and I have proof for that. I was billed for the device for a couple for months I and am currently listed as a bad payer. On the 1st of November I received a call from Zanele Mazibuko complaints analyst from MTN whom I explained everything too, I also forwarded all the emails I have from MTN stating the contract has been cancelled. She later acknowledged documents have been received and investigations will take place. Four days later I send her an email to enquire if she has found anything, I was told I am still following up. As patient as I am till to these day 29 November no one has come back to me. I am so frustrated and hopeless as I have been moved from pillar to post. I just requesting my name to be cleared. It more then a year that I have returned the device.