Thank you appreciate the advice

Hi there in need of some advice I started working for an aerial & satellite company I was totally mis-sold the job at a open day reluctantly I got offered a trainee role I was a bit in two minds as I had no experience in the field so I went along to my induction (if you can call it that) upon arrival I was greeted with chaos and the pa wasn't even ready so upon dumping piles of paperwork in front of me nothing was explainec apart from sign this sign that, I did skip read most things but she seemed to not know how to explain things clear anyway my health and safety training was to sit in front of a computer to watch a poor h&s PowerPoint presentation I left knowing the following day I was due to start a basic aerial course Upon arriving at the hotel the room wasn't even paid for so straight away that was strike 2 for me of how unorganised this company was, after 1 day of the course and speaking to current employees and hearing how bad the company actually was to work for after being sold it was amazing at the open day I decided there and then to leave after only 5hrs I explained to them job wasn't for me Anyway there now want me to pay back training course and hotel The hotel was booked at room rate it was shared with another employee and I didn't even sleep in it It was used by the employee for the duration of course and the course on the official website can be booked by the company for 220 yet they think I owe them 550 for course and hotel I'm after some advice what to reply I think it's unreasonable apparently I signed a form to say I would pay it back I don't remember this as my induction was so poor Help needed please Thank you