Tail Light problems of the 1998 Ford Taurus

Vehicle returned driectly after purchase for non-functional tail light which was replaced. Condensation was present in tail light. Bulb alone was changed. Light failed again in June of 2001. Dealer inspected car and fixed light by changing lens. Upon delivery of car tail light still did not work even though vehicle received new nys inspection sticker. Car kept additional days. At this point only lens was changed, bulb has not been checked, but car passed inspection. Charge was 224. 70 for a new lens without repair being completed. Dealer rep stated that silicone caulk could have been applied to stop leak and new lens was not necessary. Metro Ford then cleaned a "corroded light socket" for no charge. This should have been done before lens change and not price gouged consumer. Also how can car pass inspection w/o tail lights. This is a violation of nys inspection law at least. This car had been delivered as repaired and if we had not checked to see we would have assumed the repair was completed. This corrosion problem, according to Ford, is common, therefore shouldn't the problem be considered as a recall fix and not blown off as an annoyance. Please advise d wilkes.