Palm OS

I just order a treo 750 from a sdistributor to see if this unit works properly in Puerto Rico I ask to them if is going to work here, I expect to reseve the treo in a few days unlocked from vodafone, now my ? Is I have suncom wireless as carrier few days ago I have in my hand a treo 650 unlocked cingular version and works good but the data feature as email or web browser din't work well, nothings happens I call customer service they told me that if the cell phone is unlocked but is from a carrier is not going to work, I ask why they don't know that, my ? Is it is the data goig to work from my carrier to this unit? Please contact me by this message or via email thanks for everything that can anyone do for me!