Yes, don't get it fixed, return it if at all possible. Sharp has some of the most poorly engineered products with ZERO customer support. They look great, and usually work, but if they screw something up, like what you are describing, they totally and completely fail to even consider fixing the problem.
It won't be fixed, you won't have it fixed, and they will absolutely be sure not to fix it for the next 5 years. Make sure you don't recommend Sharp to others! Make sure that you insist that people go with other brands! Sharp is one of the least responsive companies that I have ever dealt with personally. It's not that they can't be reached, it's that you get them on the phone and they say "We are aware of this issue, and we won't help you, go away. Thanks for choosing Sharp!"
Frankly, you are just giving in to them if you spend one cent to fix a problem that is Sharp's and not yours. Piss poor on them!
If you must give in, then maybe a DVDO video processor is the way to go. Use whatever receiver you want, then convert the output to HD.