Ouch, sounds like a painful few months.
To sum up though, you've basically bought a dog and hoped for the best, the worst has happened and you took it to someone who clearly hasn't got a scooby how to rebuild these engines. You'll probably go off and tell all your mates they're incredibly unreliable as is the way of personal experience, but the fact is they're extremely reliable cars, strong engines too. ALWAYS take it to a specialist
Wasn't judging fella, we all live and learn, would understand if you did think that after that fiasco. Just sounds like you've been taken on a bit of a ride in all honesty.