Rafchk

Im new to the game so: First sorry if this isnt the right category for this. Second sorry if this is something super obvious. Im in the kanto department store looking for thundervolt but the tm seller doesnt have it, contrary to what the wiki says. And looking further this happens with other tms. Im just wondering if this is a normal thing and I just hace to keep plaing (I have 5 badges) or if the wiki is wrong. thanks