I lost 3g service completely one night. I was watching a movie and picked up my phone to use it, no 3g. I traveled into the city the next day, which is an hour away. Still no 3g. While I was at the office my friend who also has a Thunderbolt had 3g service, however, I did not. I talked to Verizon and they replaced my phone. That's all great and everything, except the same thing is happening. I don't have 3g service at all. Help?