You might want to call RA and tell them what you did and why, plus making sure they will issue full credit. Then call the bank/credit card company to not honor the RA charge on your account. Just tell them FedEX delivered a broken part, which you refused acceptance of. IF the FedEX delivery person did their job, they took pictures of the broken part with their tablet for documentation of teh damaged part.nobody does. they can special order it but its $259 plus 12% tax.
Not sure if rockauto will refund me for refusing the part. I'll just have to call my bank I guess. Fun times!
Keep us posted on how it goes,