R50 limit goes over R1000 with no warning

I have a a few contracts with Vodacom. One is a data contract. On a couple occasions I phoned in to tell them to please send all sms to my normal contract not the data contract. Im yet to receive my notification on my normal sim including the normal sims notification otherwise i would have known my data was finished. I also have a R50 limit so I should have been blocked but they my account is over R1000! The call centre agent cant explain y and is only interested in getting marked down. She also1st told me a lower amount and then it suddenly changed to over R1000. Im very upset especially for being a loyal vodacom client for over 15 years! This is unacceptable. This is just a way for vodacom to get rich!