In my experience saw shops usually don't have the first *expletive deleted* clue and will ruin a saw quicker than anything.
There really are no "saw shops" anymore :(
There are just hardware and discount stores that happen to sell chainsaws, and have a 2' x 2' bench and a few parts in the back that is their "shop." You're lucky if they have a guy there who knows how to take a bar/chain off and put it back on correctly.
The real saw shops that could fix anything went away with the demise of the timber industry (and of course the feller-buncher and the above mentioned discount stores).