Scammed once again

[Ape]

Yesterday I was doing in the middle of a trade when suddenly my trader left with a 500k profit.
This happend because we had a trade for 11.5m for my blackened dragon armor.
So our idea was me selling him an item first for 2m and after that he would give that item and the other 9.5m for my blackened armor.
But the item was a swift armor which is worth over 2.5m. So guess what happend, after we traded 2m for the swift armor he stopped awnsering me and logged out. I waited for about 2 hours after that and still he didnt came back.

This isn't the first time I got scammed but Knowing sts never does anything about this maybe you guys got some tips for me.