I used to pay $5.99 for the T-Zones plan until they discontinued that. I now pay $9.99 for my web plan, which is listed as "Unlimited Web for phones" on my 'My-Tmobile' account. It shows up on my bill as "Unl Web Only."
Hope this helps, it seems that you are getting ripped off.
Yeah, I never have any problems here in San Diego. Couldn't be happier, its a good deal. AT&T and their data plans are real costly, and I enjoy T-Mobile's prices and customer service. They're a good carrier.
I connect to the internet2.voicestream.com APN, in case you needed know.
User and pass are both 'guest'.