I moved somewhere where I get 0 bars on either of my AT&T phones anywhere within a half mile of my house. I called them, but they claimed that their map showed

I moved somewhere where I get 0 bars on either of my AT&T phones anywhere within a half mile of my house. I called them, but they claimed that their map showed that I had coverage, so I couldn't get out of the contract. They also said they would be adding another tower soon. A year later I got an email that they'd added a tower, but the service quality did not improve.