Welcome to the forums.
Have you tried a battery pull?
If you connect the device to your PC does it detect it?
If so, connect your device, launch Desktop Manager, go into App Loader and uncheck the theme you installed, then click next. That will remove the theme from your device and should clear up your issues.
The difference between stupidity and genius is that genius has its limits.
When you take things for granted, the things you are granted, get taken.
Even a mosquito doesn't get a pat on the back until it starts to work.
Too many people miss the silver lining because they're expecting gold.
[BES 5.0.3 / GroupWise 2012 HP2]