Having been plaged with wifi/UMA problems myself, I have a lot of sympathy for you. I was able to solve mine, I hope you can too. I have the following suggestions:
1. Start with this link: BlackBerry FAQ - BlackBerryFAQ
2. Do a search on this site, you will find a lot of posts.
3. Since the phone is new, call for support and see if it's defective and needs to be returned.