defective used car

i just bought a used VW from a dealership. after 100 miles and 3 days of driving the car the engine light came on. i took the vehicle back to the dealership to get diagnosed. it took them 9 days to diagnose my car and when they called me they told me i needed a new air pump and combination valve. i have a 50/50 warranty so it would cost me about $500. i spoke to VW experts and they told me that the dealership probably just cleared the lamp when i bought the car. i also read the diagnostic report the the VW experts and they told me that the codes don't necessarily mean i need a new air pump or combination valve but that i could just need a vac hose replaced which is typical for VW. I also found previous service reports that showed that the engine light was on right before the previous owner traded the car in and also that the combination valve and vac hose were found to be faulty. the reports also showed that the problems were given an estimate but never replaced and that the engine light was cleared off of the car this was on 10-27-07. i bought the car 2-19-08. the experts also told me that if a vac hose is left unfixed the combination valve can malfunction leaking moisture into the air pump and breaking that. if this problem was evident before i bought the car is the dealership liable to replace it. When i spoke to the manager at the dealership i told him all of my findings he told me he was going to fix the car for me but i offended him by saying that i think they cleared the lamp so he will no longer do so he was very rude to me on the phone and tried to hang up on me in the middle of me speaking.

[randalljd]

If the defect is immediate they should repair it...there is another post here last week with the same issue--and the dealer paid. You might try to search it.