ORIGINAL: durangoslt

hello...i purchased a 2000 durango slt today and when i got in to drive away,the check engine light was on and the transmission is staying in 2nd gear.the dealer didn't seem to think it was a big deal.they said they serviced the tranny and there may be air bubbles in it.they messed with it on the scanner for a few minutes with no results.they clear the code but it stay's in 2nd and the light comes right back on.now for my question.should i just ask for my check back or is this really no big deal and they should able take care of it?
thank you...