MTN - in breach of own contract

I have been an MTN customer for over 15 years. For the first time ever, I upgraded via phone.

The operator told me that I have 7 days to return the handset if I'm not happy with it. First off, the operator **** about the functionalities of the handset they sold to me. It was returned in 6 days and now, 2 months later - MTN failed to cancel that contract and I have NO PHONE. I sent numerous emails with numerous referenced codes. Nothing is resolved. Absolutely pathetic. Next stop, CPA. Since I didn't even give my consent to MTN to share my contact details with their third parties for marketing purposes. Now I'm sitting with this issue and MTN couldn't care less to resolve it, yet deducting monthly and no phone.