3 weeks into contract and still no airtime

I've recently opened a new MTN contract through Altech Autopage and 3 weeks in, I have still not received my airtime, sms's or data. I've had to top up using more money even though they've already billed my account. And now rumour has it if I don't get this fixed by the 17th of June 2015, I will be double billed. What makes this worse I've been calling almost every day to sort this out and they keep promising to call me back. They never do and it's beginning to become a bit of a frustration. I don't know if it has anything to do with MTN striking but they are not holding up their end of the deal.