I think the solution is to keep a bit of extra money in your account, so that they can bill you $0.10/min after you go over. I haven't gone over 100 minutes yet

I think the solution is to keep a bit of extra money in your account, so that they can bill you $0.10/min after you go over. I haven't gone over 100 minutes yet (Skype) so I don't know what happens, but I keep $30 floating in my account.