The first step in troubleshooting a network, software or hardware error is often to perform a hard reset. You neglected to mention what device you actually have but with most normal Java® based devices follow the first method.
To hard reset your device you would remove the battery, while the BlackBerry device is powered on. Hold the battery out for about 30 seconds, and replace. The BlackBerry device will reboot.
Note: A hard reset on a C++ based device is accomplished by pressing the Reset button.
Note: To perform a hard reset on a RIM models 850, 857, 950, or 957 device, insert the end of a paperclip inside the small hole on the back of the handheld.
This will put the device back to the way you got it from the factory. You can then go ahead and re-set up the device and not install the internet service.
Let me know if you need more assistance,