R5000 3G bill

This morning I received a sms from Vodacom saying that unusually high usage was detected on my 3G exceeding R5200. So I phoned the number and I REQUESTED to have the line blocked until I could figure out the source of the problem. Once I sorted that out, I phoned them back to turn the line back on and they refused to turn it back on without receiving a payment first. A payment for which I haven't even received an invoice yet as my invoices are only sent out on the 3rd of each month.<br> <br> However, they only contact me when my bill has reached R5000 and classify that as \unusual high usage". The monthly fee is R100 so R1000 should have already been seen unusual high usage already. Investigating further"