There must be someone in the UK that could do this work?
There undoubtedly IS someone with the technical expertise who CAN do the work, but the question is can they be bothered? I hate to sound harsh, but many bike shops just seem to be fed up with people buying bikes online (usually just to save a few quid), but then, when it all goes horribly wrong, trying to off-load the problems of fixing the bike onto them, the local bike shop.
Many UK bike shops - those that aren't already frightened by electrics and electronics - only seem prepared to service and fix those e-bikes they sold... and even then, only those where they can simply plug a computer into the bike, and the software tells them what to do. I mean, has anyone even heard of a Bofeili motor/system in the UK? That's seriously hard, left-field, whacky territory. I'd suggest nobody is going to touch that with a bargepole.
For a £4000 bike I do sympathise. But if you check back this forum, the question of "who is going to fix your bike when it all goes wrong" rears it's head many times as a very valid question when choosing an e-bike. For that reason, many here advocate either buying a known brand bike with mainstream electrics, or keeping it simple and buying bikes using generic Chinese electrics - for which several members here DO have considerable expertise to help sort your problem.
As it is, you have a very nice, very expensive, specialist brand bike which nobody in the UK is likely to want to touch. What happens if someone tries and it doesn't work... are you still going to pay them for their time trying?
It's a dilemma.