anyone know how to get that back? new here on the forum, any help will be appreciated

I'm not sure about T-Mobile, I have AT&T. So, if someone else doesn't give you a better suggestion: I'd try loading it via OTA from the blackberry.com web site. If that doesn't work, I'd try loading it through desktop manager.
You may have to resend your service books too as the version with 4.5 now requires a service book.

Regards-Michael G.

When you upgraded you probably didn't tick, or unticked the box that installs/uninstalls BlackBerry maps.
Try going through the firmware upgrade again and make sure that the box is ticked.

Alternativly, yeah, goto BlackBerry - PDA GPS - BlackBerry Maps at BlackBerry.com from you BlackBerry and reinstall it.

tried to load maps again and it says My device does not meet system requirements????????????? Any ideas?

Go to the bookmarks in your bbs browser, scroll up, there will be the telenav or whatever.