Mtn *****ing money from accounts

My account was incorrectly debited and 2 amounts. When i called mtn. They had no reason for why 2 amounts was deducted. I was just informed that mtn had an error when accounts was loaded. I dont have to pay for mtn errors. My account has also went up, but i signed a contract with a fixed amount???? Mtn is *****ing for the customer. And i have almost no service 99% of the day