T-Zone Web not working on iPhone

Ok so I have a iPhone 2.0.1 on the T-Mobile USA carrier, and have the T-Zone Web plan($5.99 a month). It used to work perfectly normal as if it were edge with pretty good speeds. Now it only can check my email with the mail and app. Safari will no longer load and says "Error 500 Internal Server Error". All my other apps such as maps, stocks, facebook etc. that used to work no longer do. Is anyone else experiencing this problem currently, and anyone have any suggestions? Already tried resetting the network settings and the phone.