cant log in

i was in champion select for my ranked promo to gold and then the game loaded. it was a black screen for about 2 minutes so i logged out and now i cant log back into my account because of my username and pasword being wrong supposedly. tried several more times and was told that my client would be reverted back to an older one. so i said sure why not not like im in a rush to get back into the game. tried several more times to log in and no luck. tried logging into my other accounts same shit saying username or password is incorrect which is bull since i am on here typing with the very same account that i have the username and password wrong supposedly. i also tried REINSTALLING the game and i get the same thing. now i've failed my gold promos and cant log into ANY OF MY ACCOUNTS. that being said before anyone says if your computer. no it isnt. i tried logging in on my laptop and my friend tried to log into my account and still didnt work. so its impossible for it to be BOTH of my computer and my friends computer.