They have been charging me for internet use, when I signed up it said on the website that internet was unlimited and free with my contract. After looking at my bills I realised they have been charging me for it, when I complained they basically said prove it, which I did. They have agreed to credit my account but I want out of the contract, theres 11 months still to run on it but I want out early, do I have any legal ground to stand on if I just stop paying?