I'm sorry to hear that... It is one of those parts that they routinely do not cover in their warranty... It was worth a try anyway... I agree with your distaste in dealing with DC... I'm going through something similar with incorrect part #'s...

Be careful with those pot holes and sewer covers with these low profile tires... it transfers the shock directly to the wheel and pinches the sidewall against the rim... Thus creating a future sidewall failure...