eBay Cheapy bulbs melted connectors? Now What?

A buddy of mine bought $5 headlight bulbs on eBay, they ran good for a while, then one went dim, the same night both headlights went out. When we inspected the next day, after unplugging the bulbs, the ends of the connections were a little burned. Plugged the stock ones back in, and those were fine for about a month. Now one headlight is dim again, do the ends need to be replaced. Will a dealer replace under warranty if the stock bulbs are in now?