I went on faster fibre through chat on 5th Nov. £35 per month , just had a £58 bill, when I queried

I signed a contract through chat on 5th Nov for faster fibre ,Tv ,unlimited calls and unlimited broadband for £35 per month . Got a copy of the transcript. Just had a bill for £58  contacted them and they said I had no contract with them last one signed was in Nov 2015 any idea what to do next.