I've really enjoyed my Exhibit II 4G on Tmobile for the past year or so. It's worked great so far, even when I am indoors. But I recently started a new job and when I am at work, I get no signal whatsoever. I can't make calls, check emails, or access the web. Is there anything I can do to increase the signal and resolve this problem? If not, are there any other phones that I can get that would have a better signal? I am currently on the $30/month unlimited data plan so I need a phone that I can use on the same plan.