That's weird. You would think they could just run the AC and watch the drip and see where it's coming from. Has anybody tried pulling the top off the AC unit and putting a garden hose in the drip tray at a low rate and let water run for 10 minutes? I would ask them to pull the AC again and turn it over and see if maybe the drip tray is damaged or something. While it's off is the roof flat under the unit or is there an uneven seam in the decking that doesn't allow the gasket to make a good seal? Sure would be nice if we still had Doug Rainer on this forum to give some input.