Unhappy and Disappointed customer

I have a contract with MTN for many years. Last year (2017/09) it was time to upgrade. I bought myself a Samsung S7 Edge for R15.399. The contract stated that it will repair the screen if broken only once. In October I booked my phone in for screen repair which was also damaged at the back. After 3 weeks I received a message from MTN Insurance quoting me R3700 for repair. I called their custom services to get clarity on why I've been quoted for something they are supposed to do for free. The Agent told me that they are charging for the back of the phone that was also damaged cause its a package. I have asked the lady not to continue as I felt this was unfair. It was returned on the 2nd of November(02/11) with an issue of charging. The following day(03/11) I took it back to MTN complaining about the problem, because before the booking the charging part was working fine. After 2 weeks I received the message from MTN Insurance quoting R7417.91 for fixing the problem. I again called and asked them whats with the quotation cause my phone never had an issue of charging, it only had an issue after it came back back from the Insurance. The complain was logged, but even today I'm still receiving the message that my IMEI number has been assessed, quotation R7417.91. Its been fully two months without my phone, and funny enough MTN is still debiting for their service. IME no: ********** ****3665 Job card: ********** . I dont know what to do, I feel so helpless, Hello Peter, your assistance will be highly appreciated.

Regards