Bought used bike from garage, advice needed

Hi,I'm in the uk and recently bought a CBR600RR from a dealer some miles away from me.It had no fairing protection, having done the job several times before, I bought some sliders in advance of delivery.Upon delivery I took the bike out for a ride to make sure everything was as it should be, all was excellent.The bike is for the Mrs, so I took her to a nearby car park so she could get comfortable with it, having never ridden a supersport bike before. We were out for less than an hour. On the way home, just down the road from the house, the bike cut out. Refused to start just turned over.We walked it back home. I checked it over, it's a code 18 problem with the cam pulse sensor... annoying but no problem we'll get the garage to pick it up, fix it and bring it back. At the end of the day sometimes these things just happen. I emailed the garage of course they are closed for the Christmas period so didn't expect a response any time soon. It was here I made my mistake.I figured while the bike was off the road over the Christmas period. I could do some work on it, as it's too tall for the Mrs it needed lowering and it needed sliders.I took off the fairings, cut the holes and fit the left slider fine. When it came to undoing the right engine mount bolt it was very stiff even after 'cracking the seal'. After around 1.5 full turns there was a large 'crack', the engine mount had sheared into several pieces. Upon inspection, the engine mount bolt was very obviously put in cross-threaded by someone previous: https://imgur.com/a/5VMoPRw​I now have a bike with a 30-day warranty, that doesn't start, and has a missing engine mount. I've no doubt the garage will fix the 'not starting' issue under warranty, but I have a feeling they are going to say "You sheared the engine mount, your problem".​I realise now when the bike broke down I shouldn't have done any work on it, however, this would have happened at some point regardless. Anyone any ideas where I stand legally on this? via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/eivyrr/bought_used_bike_from_garage_advice_needed/?utm_source=ifttt