Looking at my current Audi, I'm guessing that the OE caliper was Zinc plated for corrosion resistance (Cadmium used to be the metal, but due to health hazards is pretty much out). The sand blaster took the Zinc off, leaving bare Iron/Steel without protection.
I agree with AndreasPassat, that a letter to someone of authority in their Customer Service department would be a good idea- you might be offered a promotional discount, for instance. Keep the letter short and to the point, don't threaten, just say that you have influence with plenty of their customers, and that you are somewhat disappointed to receive a rusted part unfit for use, and a dismissive attitude from their representative when you called to complain. Actual letters are kind of rare now, and get attention.
I agree with AndreasPassat, that a letter to someone of authority in their Customer Service department would be a good idea- you might be offered a promotional discount, for instance. Keep the letter short and to the point, don't threaten, just say that you have influence with plenty of their customers, and that you are somewhat disappointed to receive a rusted part unfit for use, and a dismissive attitude from their representative when you called to complain. Actual letters are kind of rare now, and get attention.
