was about to sell my account so i went to change the password they sent me the link  i changed it tried to login it was saying incorrect so i sent another password reset and they locked the account? but i have no idea how to unlock it. didn't log in the account for about 2 weeks prior to this.

well i would assume they want you to verify your account through your email if they doesnt go to account settings and try every password you got to see if you can recover it or not.

yh yo uneed to provide information of ownership.

Looks like you can't unlock the account then.

did you buy the account? if so then the owner tried to recover it i guess and jagex locked account because they dont know whats going on and witch one is owner

You just need to provide proof you own the account to unlock it