As always, the "better" BlackBerry is a matter of personal choice. If you have a few days before you have to decide to return yours, visit a retail store or friends that have BlackBerrys that you are interested in. Play with some of the other models, ask specific questions about how they work ( more detailed that "what's better"?)
1st Step in Troubleshooting: Do you have a BlackBerry Data Plan?
2nd Step in Troubleshooting: Pull the Battery.