This is a shot in the dark, but, .....
I see you are on T-Mobile? Happen to have an WP7 or rooted android phone?
Go the tether route, it really is your best and only solution.
Many, many options at that point, from paying for a tether plan to *ahem* 'circumventing payment'....
- for instance -
I have an HD7, the last update HTC gave out included 'internet sharing' - basicly a mobile hotspot when turned on - and I have not paid for, nor have been charged for a tether plan *seems I got lucky*
As far as android is concerned, there are some apps that will do tethering for you, and sets the data through a proxy, as to lessen alerting the phone co. as to whats *really* going on.
Good luck to you!
HTC Dream / CM6
Samsung Galaxy S III 16GB / Stock Jellybean
Archos A101IT 8GB / SDE: Stock 2.4.80 / UrukDroid 1.5
Acer Iconia A500 16GB / kjy2010 Honeylicious HC 3.2