So recently my WoW sub ran out. I normally pay with my debit card but it happened to be drained this week, so i decided to try the "pay with phone bill option". It states you can not pay with cell phones voip or cable phones; i'm using comacast and decided to try it anyways. Turns out it went through and i was able to play for the day and the bill never went through =D. I've done this for a few days now but I'm not going to do it just in case there is a chance of getting a ban.
Now to clarify some things, When you pay with the phone bill feature they say you will receive a conformation call within 24 hours; but if you call with cable, voip, or cell you wont get the call and can play for the day for free.
This really helps out if you are in a tight spot with money and such.
EDIT: use at your own risk! Like i stated i've only done this a few times and do not know the chances of getting caught are.