Please help.

I cant login to the riotgames Website. I can use the client but the website just doesnt let me login. ive tried the same exact password for both. login out of the client and back in. copy pasting but it just doesnt allow me to login on the site. ive deleted cookies updated my account (new lol stuff or something) but i just cant get in. i want to login to change my name thats all..