Disappointed and disturbed customer care

I had taken a mobile contract tablet with mrpmobile. Firstly when I took this contract it was over the phone about three months after taking this contract the tablet froze and refused to come on I tried to contact someone from mrpmobile but had no joy. I even went to mrp clothing and had no luck, so I ended up paying for a broken phone has I didn't want to get blacklisted. I am now over 5 years later and I am still being debited. R90 over 5 years is a lot of money I put a stop on this debit but I am so afraid of this causing a bad payment history on my name. Please can I get some assistant has I would like to know what's the next step.