I’m still of the opinion that this is a troll.
The OP is so full of obvious fail that it can’t be anything else:
Leased a bike for a thousand million pounds; fail.
Received a bike that wasn’t correct spec; fail.
Rode incorrect spec bike; fail.
Unhappy with incorrect bike forks; fail.
Unhappy with incorrect bike fork and chain setup; fail.
Contacted company who suggested you fix it yourself; fail.
Riding incorrect spec bike with dodgy fork and chain keeps breaking; fail.
Crash incorrect spec bike with dodgy forks and dodgy chain (x2), then discover crack in frame after crash; fail.
Still paying £200 a month for bike that supposedly cost £6,000 and have had no service, no comeback via insurance and now no bike at all; fail.
If you need to ride a 6K bike, you’re either really, really good or you’re reading too many magazines and are falling for the marketing in a big way. If your story is true, you’ve made so many errors right from the start that it is difficult not to view your story in a less than sympathetic way.
I hope you resolve things, and I hope you learn a number of very important lessons, but you don’t appear to be receptive to them at present.