Call customer service and be persistent, patient and polite.. Regardless of past offenses (BTW I dont agree with the way you handled the wet iphone), you paid for an iPad with a good wireless antenna. This is a known issue with new iPad which Apple has acknowledged. Don't give up until someone at Apple helps you. You probably just got a dud at the Genius bar. It happens. Most are very nice but there are a few that aren't.
What really surprised me was that I actually dealt with three people at the Apple store. First it was a regular genius bar guy which didn't help me, so I asked for a manager which also was of no help.
I left, and then though about doing a video recording of the device malfunctioning, so I called back and asked for a manager to see if a video would suffice. The manager was a woman, so it was a different person than I saw in store, and she also wasn't able to help. She did suggest to call Apple support as they may be able to help where she can't.