(Just joined yur forum today, but I work in this industry... Hope you don't mind if I comment?)
BWA had a good point... Changing / upgrading to a better phone almost always helps.
You should check T-Mobile's coverage maps on the web. If they show strong coverage in your location, then call and gripe. The more complaints they get, eventually an RF Engineer will receive a task to study or "drive-test" that area.
Also, if your coverage area is clearly indicated, and if your phone automatically "roams" to another network, you can usually call your carrier and get them to erase the "roaming" charges, since it's clear you were in their advertised coverage area... A few instances of them paying another carrier for your roaming in your home area will usually trigger a drive-test through your neighborhood.
Keep in mind, if you're truly in a dead zone, it takes approx. a year or more to actually add capacity to the nearest site, with budgets, zoning compliance, etc.
Good luck. Hope this helps.