I just watched my bumper-ed iPhone 4 go from 5 bars to 1 bar and back to 5 bars while sitting on my desk untouched. This has been consistent since I've owned the phone. I'm thinking I'd like to get it replaced. I know the time window for returns is 2 weeks but I want to continue to be an iPhone 4 user...just with one that works. My thoughts are to wait a while and then contact Apple Support for a replacement but I don't want to get outside of whatever window allows me to do that. So, is the 14-day thing just for returns/refunds? The phone is under warranty for a year, right?