You have 3 belts total. Outside belt is going to power steering pump, crank, and a/c. Middle one is crank, a/c, and alternator. Inner one is the fat timing belt hiding underneath the cover going crank, intermediate shaft, idle pulley/tensioner, cam.

The outer belt you speak of is tensioned by the power steering bracket. If you took it to this guy for a/c work he had no business playing with the power steering bracket unless he replaced the a/c compressor. I would take it back and demand he fix it.

The only other thing I could think of would be you took it to some other asshat before who over-tightened the power steering bracket, which ended up shredding/melting the belt. In that case, go back to that asshat.

Or... Buy a new belt, and do it yourself. It's really not that difficult. The power steering bracket will throw you off at first, but it's a pretty simple design. Lightly tighten the bracket itself, then tension the bolt, then tighten the bracket.

Or... Buy a new belt, buy me a 12 pack of Steel Reserve, Marlboro Reds, gas money to and from your place (avg 20 mpg) and I'll do it for you