Hummm.... I've been with AT&T for a long time and Verzion too... quite honestly, I've always had a great experience with AT&T people... not so much with Verizon. In fact Verzion DSL people are all but worthless. They don't listen and only know their script. I had to tell one "tech" on the MacOS support line 10 times if not more..... "I don't have a Start Menu... I'm on a Macintosh" and his response was... "Okay Mr. X, Go to your Start Menu and select....". UGH!
None of them are perfect is all I'm saying.
Same with AT&T Fast Access DSL, and cell service: terrible service.
Even when I wanted to activate my iPad 3G, it was a pain to get someone who actually knew how to activate the service. I was transferred several times to other departments, until I got Apple involved and they found the right contact to speak to.
T-Mobile, on the other hand, great service. In several occasions, I had to unlock my smart phones because I had to travel out of the country, and T-Mobile did it for me quickly and free.
Good luck on getting AT&T or Verizon unlock your phone so you could take them on your trip and use a local SIM card and service to make calls.