Hey there… I recently bought a Gift Card to a guy that was selling really cheap (100$ Xbox Gift Card for 67$) he didn’t have good reviews or any above 5$ so I took a shot there, I bought it and then he send me a fake code, he immediately told me that he was sorry and he will cancel the order, so he did and I got my credit back. I noticed that he already sold at least 4 more gift cards from 100-200$ range value and he still hasn’t any review for those sales so I assume they also failed. So I think he is only doing it because that way in his profile is appearing that he successfully sold those items when he didn’t.
This may be a bug, cancelled transactions should not appear as an item sold in the profile because people can confuse due this.
