02 S80 T6 Volvo Dealership Incorrectly Installed Timing??

[T_Bone]

I bought this kit from FCP Groton..

http://www.fcpgroton.com/product-exec/p ... _2000_2002_

The parts were part Asian and the Belt was Mexican made. I hadn't heard anything bad about them. I also had to buy a new water pump from Volvo and a new serpentine belt.

They also replaced my coolant for me. (They didn't quite add enough)

A week into driving it I started hearing a slight squeak like a bad bearing either in the s belt or timing area (couldn't pinpoint it).

Two days ago I got a check engine light and got the codes read at auto zone. Camshaft Position Sensor "B" was throwing a code. They say it must have something to do with the timing. Perhaps the belt jumping.

Any idea what could have happened? The dealership did all the work but I gave them the timing parts, if the parts didn't fail (because they are non-electric I.E. a belt and some pulleys..) wouldn't it be their fault? So they would need to take care of it, right?
I'm taking my car to get the front half shafts replaced Tuesday. Any idea what I can expect?