Cannot make voice calls

Since I upgraded to a new contract I can make no voice calls even though I have a positive balance in voice minutes. I have been trying to get help from Vodacom, and every time I am transferred to another department. A request for service has been logged with Customer Care.

Now I am being billed for using Vodacom USSD and for sending SMS's, even though I have around 200 SMS's left on my bundle.

And... while trying to contact Customer Care once again, I am notified that I exceeded my customer care limit for the month... I can contact them again after 2 Dec.

So I am stuck on a new contract with a new device but I cannot make calls or send SMS's without incurring extra charges. And I cannot contact my service provider for assistance...