WORST SERVICE PROVIDER EVER

So in September we phoned MTN, giving 30 days notice that they do not renew our data contract when it expires and cancel it. The next day we noticed that all our contracts were cancelled with immediate effect. My husband phoned them, and they reactivated everything. When they debited our bank account beginning of October, they deducted R1 981 more than they should. We phoned again, just to hear they charged us for early termination. WE NEVER REQUESTED EARLY TERMINATION!!!!!!!! After about 100 phone calls and being send from pillar to post, MTN says we never requested the cancellation. Good heavens - how on earth does MTN do business - we want our refund and suddenly they can't find anything where we phoned them. I AM SO FLIPPEN FRUSTRATED AND DON'T KNOW WHAT TO DO ANYMORE - Hopefully someone at MTN reads this post and will make contact to help