An AT&T customer who switched to the company's FirstNet service for first responders got quite the shock when his bill came in at $6,223.60, instead of the roughly $260 that his four-line plan previously cost each month. The Texas man described his experience in a now-deleted Reddit post three days ago, saying he hadn't been able to get the obviously incorrect bill reversed despite calling AT&T and going to an AT&T store in Dallas.