Belf mage unable to learn Teleport thunderbluff

Hi, i am a lvl 40 belf mage and i am still unable to learn teleport thunderbluff, i have every other city except that. i cannot find a solution to this and am wondering if this is some bug or that its normal that no mage can teleport there?

EDIT: I HAVE BEEN to the cave of Undeads in thunder bluff where the mage/portal trainers are. the portal trainer isnt even giving me the option or showing me the option to learn a portal.