Originally Posted by mconlonx

Bring it back to the shop and have a conversation about it. Don't start off accusatory, just describe the issue and ask what they can do for you in this situation. If they want to charge you for new crank plus install fee, consider a different shop. Hopefully, there would be some kind of compromise--an average shop might do an install of a new crank you buy there for free; a better shop might credit the cost of the used crank toward purchase of a new one, or at least give some kind of good will discount off a new crank.