Sloppy communication

I'm so frustrated with MTN!! I'm living abroad and my contract is still active with them and my deductions have been going off my South African account faithfully every month but for the month of October they have decided to deduct a R1000 more. I've sent an email because that's the only form of communication I can use but no response from them. I had asked my sister who is in the country to go to a store to try and find some type clarity of on the situation and they just said they've never assisted a customer abroad. I haven't received any statements from them at all!