Non billing of account

I've come to reach a point where by I feel like Mtn is falling me as their client. On the 30th of March 2016 they sent me an sms saying my account is overdue with R440.00. what surprised me is that they already saying they are going to suspend my account if I don't pay that amount. I have agreement with Mtn that they must deduct the contract money monthly from my account which this month of March they failed to do and they want to make it my responsibility to do while when they deduct they never say a word to me. the sms send to me has their ABSA account number only which doesn't even have Ref No or even branch code and name for that matter. How do I know that this is a legit Mtn Account number or that the sms is indeed from them or its a *****?<br> when I make a call to the call centre to make follow up am told I must first get bank statement than call the and confirm that no debit was made than they will give me Ref no. I mean how inconvenience and unprofessional is this from Mtn? why cant they ensure they rectify their mistake of not deduction than have to make me do up and down at the bank while we have agreement.Am not happy with Mtn contract service at all. attend to this<br> <br>