Received a R5600 account

Afternoon<br> <br> I have a 3G contract and it's always been between R190-R210 per month. I specifically request my data contract to lock as soon as my purchased data usage has been reached. This is ridiculousness. I was considering moving my cellular contract over to Vodacom, but after this I'm very skeptical. How can this happen all of a sudden? R5 600 I don't have.<br> <br>