I think
@Cyclopath1000 has a point.
It's not totally clear what your agenda is.
You don't seem to want help - other than asking for a good solicitor and I'm sure there's better places for that than here.
You're obviously unhappy with the bike as you said :
the bike is less than six months old and been trouble from day one
You might have a legitimate complaint - maybe the bike has been nothing but trouble since day one. Generally though a shop will try and resolve problems. You're obviously able to ride the bike, or you wouldn't be in this situation ? So is the problem the bike or your expectations ?
However, from what you've said, you just seem to want to complain and point out that you're correct and Fantic are crap ? (Now I'll be accused of being a Fantic Fan Boy

)
and it turned out its my fault for riding it in the damp and washing it
A bike shop is not going to say it's your fault for riding it in the "damp". The bikes are more than capable of being ridden in the damp, wet, water, mud. The problems arise with how people clean them or if they drown them. If a cable has split, which can happen, then obviously it won't take much moisture to cause a short circuit. It seems this was the case and they changed the cable for you. You had a problem, they fixed it - you're complaining ?!!
Now you have another problem and you've decided its the same thing. You've looked on line and found the Fantic cables are "crap" / different to the other ones you've found, when the case is more likely that Fantic have upgraded the cables with an extra layer of shrink wrap to protect them from moisture ingress if there is a split.
In some random gesture you've put up an extract from an online Specialized bike manual, which doesn't even say if it's for an e-bike or not. I'm not sure if this is some way to prove that it is ok to drown your bike - even though it's obviously not and all the manuals will tell you to take care with water around batteries/motors/controllers and so on. Unfortunately, in doing so it just makes you look more irrational in how you're dealing with this and presenting it.
I guess the big question is ... what is your point ?