My contract ended Stop taking my money

Dear MTN I'm very much disappointed with your services, I've been loyal to you guys for years,I had a Contract with you guys and I've played you until it ended but you're still deducting my money mess-uping my credit records because every month I have to reverse my money, when I call you for help you drop my calls when I go to your shop they tell me that there is nothing they can help me with I have to go to 14avenue to solve this, why are you doing this?its been long going up and down trying to sort out this mess Please do the right thing.