[Q] not getting data at all? topic

Heya! My friend gave me an HTC one m8 (verizon) after my at&t was stolen. I popped in the sim card and I can make calls and send txts and all but no data. I tried changing roms and flashing kernel but nothing seems to work. called att and after some adjustment they made to my account it still didnt work. went to att store to change my sim card (they said at support that it might be a sim card issue) and still I get nothing :( I know that I wont get LTE but having no data at all just sux. Do you know anyone who is using ATT sim card on verizon m8?? or maybe can someone give me directions on what to do? Ive been reading about it for past few days and I see that it works great for tmobile users.

Im rooter, soff, unlocked and cid 1.
please help?