I perfectly understand the way you feel and fully support your reaction... except that we should not lose our sanity or mental health because of these dishonest guys. Just to let you know, something very similar happened to me: when I negotiated my car, the CA threw in a few accesories to get me to make the deal, including the M3 mats. Fine. Long story short, I had to fight this up to the morning I was picking up my car at the Performance Center!!! That morning I had no other choice than to raise my voice on the phone and clearly threaten them to give a bad review with BMW NA so that they would finaly fax over the request to the Performance Center to put the mats in the car (which by the way I was so lucky to get the M3 ones as they had been on back order for several weeks before).
Anyhow, I perfectly support you here because it is about the PRINCIPLE. I actually feel the same way on the road: if a guys seems to be lost and/or puts his signal I will let him go in front of me to allow him to exit the highway/road... but if I see that the guy is simply trying to screw an entire line of cars which, like me, are following the law and/or just tries to gain one more place in a long line....then SCR@@$$ him!!
Anyway, good luck to you!
2008 M3 Coupé | 1995 M3 LTW | BMW CCA Instructor