[gradius2006]

i just bought a htc evo 4g from ebay and the guy said it was unlocked but i tried to hook it up with sasktel in canada and it doesnt work it just roams and the internet sucks and i cant get 3g
is their anyway to unlock this phone its a cdma?
or anyway to get it to work with some of the service providers here like rogers or telus??

any help would be appriciated
thanks