MTN playing games with my money

Someone took a ********** cellphone contract under my name in 2014 in the Eastern Cape, I have never been there, reported thr case to MTN branch in 2017 after the person went and took an upgrade still under my name. Since 2017 Jan they have been doing and investigation and eventually finalised it in August 2018 and the refund approved. The refund is what is not getting to my banking account, I have called a 100 times, have been given ref numbers every time, nothing has changed. Now they want proof of payment from me from 2014. My bank only gives bank statement up to six months. What now MTN?