Billed 5 times more - Utterly disgusting service

I am utterly annoyed that my account has been billed/debited 5 times more than my normal amount, in previous months.<br> <br> Usually I get airtime/sms/data every month as per the contract I chose but the airtime has been non-existent for the past 3 months and all of a sudden in the beginning of May, I \reached my limit"which has never happened before. <br> I have an open line on my MyMTN Anytime 100 contract but my bill has never exceeded the monthly payment nor do I exceed extra costs yet today I was debited R2930.50 to be exact which is all my money in my account"