Banned?Not sure why

Hey, my previous account sumer, associated with the email sumersinha@gmail was banned earlier (this was around an year ago) when I was a member of this site. The ban had happened after I had posted my account trying to sell it. I am not sure why I was banned, and therefore have created a new sythe account to try and sell my runescape account. Please provide me more information about the ban.
Thank you!

 

Can't seem to find an account, please post a dispute with the name of your old account.