Here's the deal, the stuff in the trunk is a Mercedes tested product...it won't kill you or explode. I happen to have done business with Town Fair Tire in the past. Not saying that this is the case but I think if you went to another Town Fair location, they might treat you differently. It all depends on the management. They give you a warranty with your tire purchase and it has a road hazard rider with it. You hit a road hazard and were out of luck for some immidiate help. The tire was punctured to the point that it was not repairable (the sidewall). Once that occurs, no matter what you do to get back on the road is irrelivant. They should replace the tire with the same one. Tell them that if they don't they have lost your business. If need be, call the corporate office and tell them of your plight. I think you will get a new tire for little or no money.
Good Luck and don't be afraid to mention that you have a load of friends with the same car and they could loose not only your business but a whole bunch of crossfire owners.