Recovery tests are usually performed by OMMs or the buyer. The buyer, after purchasing an account, receiving all of the creation information from the previous owner. In order to test this information to see if enough of it is legitimate, go to https://secure.runescape.com/m=accountappeal/passwordrecovery
Fill in the fields. It will prompt you to enter the registered email on the account. (ENTER AN INCORRECT EMAIL UNTIL IT PROMTS TO RECOVER THE ACCOUNT). Then enter all of the information that you have. Wait 6-12 hours for them to reply to your email if the password reset has been accepted.
Don't buy accounts from people you don't trust. Any original owner can recover their account.