Oh yes take it back. If I were you the first thing I would do is get the repair manual out of the library. Then show them the step about removing the pully and replacing the key. There may even be a warning in the repair book. This show them that you know they had to remove and replace the pully as part of the job. Tell them the car was fine when you came in. Tell them you brought the car in for service in 'Good Faith'. Then point out you think what they did caused your problem. Don't forget to stay cool and don't lose your temper. I can tell you for sure they will say no way they caused this. Good luck.
K&N open air filter from Rspeed, 4-1 Header from Good-Win Racing, Header Blanket from Track Dog, 2 1/2" midpipe with resonator removed from Insane Muffler, RoadsterSport muffler from Good-Win Racing, Matching Hardtop from a 90, FM springs sways and KYB AGX 4way shocks,shock tower brace, chrome gas door