OP: I am a former bike mechanic and sorry to hear about your crappy service. Like any service company, there will always be a few employees who don't give a rats a$$. Hopefully you will find a mechanic who takes pride in the service that he/she gives. Re: squealing brakes...don't worry...not a safety issue....usually means the brake pads or rim is dirty. First make sure that the pads are toed in (front of pad hits rim first). If it still squeals, clean the rim and pad with rubbing alcohol. (a neat trick is to rub sidewalk chalk on the rim...squeal goes away). I would suggest you attend bike maintenance 101 (free at REI). Tuning a bike is not rocket science and is really quite easy to learn.....It's just knowing what the limit screws do. (basic tuning for the shifters is just about cable tension). Good luck and hopefully you will have a better experience.