Ridiculous amount on my statement

So Vodacom has sent me a bill in the amount of R1185 after I had explained to them that the guy who put me on the contract did not explain the terms of the contract clearly. There is no way I am paying R1185 for a phone. Vodacom claims I used R447 worth of data when the onus was on them to cut me of after I had reached my limit because they understood the nature of the contract and the background and the may complaints I've laid against the service provider. <br> <br> I kept checking on the Vodacom App and to my understanding I still had data. There was never a point where I used data outside of what they allocated to me. I AM NOT PAYING YOU R1185!!!!!! NEVER! NOT HAPPENING<br> <br> I want to cancel my contract with this service provider because clearly they are in the business of ripping people off, all in the name of having the best coverage in the country! I'd rather struggle with network and be a happy customer than have the best coverage but remain frustrated each time!!!!