cell c debit after cash payond and charge buble penalty. and misplace payments

I have had so meny trouble with cell c. I made my mayments on the 29 of March. My debit date is the 31 of every month. So i have emaild a letter asking them ti stop debiting as my bank account is not working at this moment. I started making eft payments en January. And made the request then. So after e eft the payments on the 29 March myvline was cut off on the 20 th of April. They could not fond my mayment after a week of sending proof of payment and fighting they found my mayment in one of my uther contrackts. And transfered it. Now they charge me R75 on 2 lines for missed paymond. So i am paying dubble fines for there necligence.