PATHETIC:Taking money off my account while in credit

If I could rate THIS PATHETIC SERVICE FROM MTN I will give it a - zero zero zero!!!! Unbelievable They 1st deducted Dubble installment in April. Then customer care told me they will NOT DEDUCT this month because they are sitting with a credit of 1month deducted too much!!!! Tonight mtn went and deducted another installment that caused my house dt order not to go off. You are the worst!!!!! Why did I waist my time to phone you last month if you just go and deduct again and again!!!!! ARE you serious!!!!!!! What the hell I tried phoning customer care 135... You are going from one voice to another but NO CONSULTANT TO TALK TO!!!!!!!! WHERE ARE YOU!!???????? You are taking money out of our accounts while sitting with a full month credit