G.E telephone which was bought out by sprint did this to a friend who lived in their coverage area (but ironically 200 yards from my SBC covered house). They said the same thing, it's just the way it is. We called the public utilities commission of our state and complained about it. Within two weeks he had a credit amount on his bill and evidently the phone company had to pay back quite a few people. This was shortly before Verizon purchased them.
I'm not surprised Verizon sprint tried this too. I had the nextel phone because of specific coverage and when sprint purchased them, they attempted to charge me more as well as failed to maintain coverage areas. They would call me about 3 times a week, even after being told not to call any more several times, to request I purchase a sprint plan along with a new phone and 2 year contract. I told them my contract with nextel wasn't up and they explained they owned nextel so it would be ok and I explained to them that if they owned nextel, it shouldn't matter but if I was changing contract companies, it sure as hell wouldn't be with the company that screwed nextel coverage up.
Sorry about that tangent. The point is, check with your state utilities commission when crap like this happens. Every state has one but might call it something different. Often just having them look into it is enough to get them to fix the issues.