Poor service

I took out a contract with mtn, application was done over the phone with the guy called Ernest Mngoma. That was on the 27th of July. On the 1st of August i sent Ernest Mngoma an email requesting him to call me back as I changed my mind about the phone. He never called, the phone was delivered to my place on the 06th of August and I took it to the mtn store on the 7th of August, as I was advised if am not happy with the phone I must take it back within 7 days. After taking the phone to mtn for cancellation of the contract, the contract was never cancelled till today, I called Ernest Mngoma and I struggled to get hold of him, he promised that contract will be cancelled within 72 hours,till today it was never cancelled. Can someone please give me a call on *** and resolve this matter for me, because now I’m sitting with contract under my name, but I don’t even have that phone with me