Oh man, that's totally no good, but I think we can tackle this issue and get it resolved. First off, have you looked at the exact address in Dallas where you're having the trouble? The area's pretty big so searching the address on our coverage map will give you a good idea of what kind of service you'll get there. Please let us know what phone your using as well. There may be some setting we can change that'll help. Also, have you gone to multiple locations in Dallas to make sure it's not just happening at a specific address?
Did you still need some help? Please give us a reply and let us know how things are going.