1998 Honda Civic Belts Shreaking

Hello all, I just recently purchased my car about 2 months ago and have been having problems with my serp belt from about 2 weeks into having the car. The noise that has been coming from it isn't like any other noise I've heard from a belt going bad or from a loose belt, etc etc. Its more like an extremely high shreak that makes you want to pull your hair out. I took it to my mechanic and he replaced ALL the belts and I know he did everything right because I watched him do it all. (Found alot of other things wrong with my car in the process too. Bad motor mount, torn axle boot, semi bent axle, etc etc) The shreaking stopped until about a week and half after they were replaced. Anyways, I've tried everything from changing all the belts, putting solution or belt dehydrator or whatever these "quick fixes" are called and nothing. I've tried taking the belts off and lubing the pulleys and bearings, which worked for a bit but only for a week or so. I really hate for my cars to make any kind of noise at all and I need some tips. I think it make be that the bearings in the alternator are going bad, so that may need replaced. Or the tensioner, or pulley wheels, I just don't know. Some help here please? Thank you in advance- R. Wiesen