Character sales

So i posted one of my toons for sale on the site and had a reasonable offer come in for it - that is lower than my posted price. I cant find anywhere that says when i posted the character or where i can cancel the posting or change the pricing. Pretty sure the guy is ok with waiting if i can tell him how long it will be - but again it doesnt even say when i listed it or how long the listings last (i know it said it when i posted but i dont remember)

in the panel where you can set a price for your character, there is a tab "character i'm trading".
Click on it -> now you see all the characters you have on "trade" and there should be a "cancel" button (or something like that)