Reporting RS3GoldMart as a scammer being a middleman

I was aiming to sell my RS 07 account (http://www.sythe.org/showthread.php?p=15144205#post15144205) and decided to use 'RS3GoldMart' as a middleman as he had enough vouches and was a $50 donator/SVU.
Little to my knowledge would he then go on to request all my details, log onto my RS 07 account to 'check' it, meanwhile buying it membership and removing all my wealth - none of this to my consent.
In my Sythe selling topic, my items are pictured, however when I go to log back in on my account, I was left with a surprise of having everything gone.
https://gyazo.com/73292a61bb6b426adf566e17fbec16f7

I will now show the Skype conversation:
https://gyazo.com/5ca722e2d86a4f13be25912d04fefd60

RS3GoldMart confirming we were talking to him:
https://gyazo.com/179700501d29df2d279fe88724be04a8

This man/woman has scammed me for around 15-20m 07 GP, completely emptying my bank. He claimed he was a middleman but has taken my information to 'check' the account and ended up transferring all of my items.

I hope justice is served. Thank you.