Originally Posted by nesteel

I'm just going to say it: you're a nightmare customer.
If you're brakes worked when you picked the bike up, the rest was an unrelated problem. Bring your bike in every year for a checkup/service, or learn to do it yourself.
As mentioned, the only error the mechanic made was not going over your bike and advising you of the other issues (and it sounds they were there) it had.