My hubby and I were recently shocked by our bill as well.  I'm a real estate agent, thus on the phone a great deal.  We moved to a 1400 minute plan YEARS ago because of my constant use of the cell phone.  I use it 700-1000 minutes per month to his 200-300 minutes. 

He called and talked to them about his options since he was deploying.  They told him they could suspend his number, EVERYTHING else would remain the same, just his number would be affected.  At least that is what he understood.  So imagine my shock when I received my bill to find that for some reason I'm now on a 450 minute plan, 2900 roll over minutes had been removed from our account and I was being charged $20.00 for texting. Total, I'm paying 89.99 for a 450 plan with texting and data! 

I think the information itself or the way the information was presented was very poorly conveyed!  The rep I spoke with last night said, well you can't have a family plan when there is only one person and you can go back to that plan when he returns.  I said, that's great, but in the mean time I'm going to pay an ARM AND A LEG to use the phone since I'm the one who ACTUALLY uses the phone.  This month I used 775 minutes.  At 40 cents per minute that would have been an extra $130 on the bill had I not had roll over minutes.  Before Military suspension bill  = 173.00.  New bill (had I not had roll over minutes to use) = $220.  NOW THERE'S A MILITARY SAVINGS FOR YOU!  The rep did add 5,000 roll over minutes back to my account, but I just hope that I don't use all of those in the next 9 months. 

They did call to confirm his military deployment and we played phone tag in which I ended up leaving a message stating yep he is deployed.  They also sent an e-mail regarding 'recent changes to my account'.  However, I was never able to get any links to work that was suppose to tell me what those changes were.  I just assumed it was, yes, military suspension.  I had no idea that my number was going to be effected as well.

He said he is ready to look for a new carrier upon his return.  I've liked AT&t and been with them since 2005, but these types of miscommunication are very costly.  Luckily I caught this and had some roll over minutes to use. 

My recommendation.  If you are in the military and have a family plan, DO NOT SUSPEND your service, especially if your spouse actually uses the phone.  If you suspend the service, you will end up paying far more every month in the 40 cents per minutes that they go over, then if you would just keep the phone active and off while you are away.