I guess the actions of the mechanic are accepted by most as one of those things to get over, I wonder how many people will not have been lucky enough to realise something was amiss and then subsequently left with a hefty bill.
I have no doubt the problem would have been solved by the repair company by now if given the chance. Obviously the OP got a cowboy on a call out and should have accepted the offer to make amends rather than opting for the legal route. Hope the wife enjoyed the wine!