I don't have much proof of this but its worth a try.
IGN:OsamaBeenLaggin9
(First Report:Sorry if it's bad/incorrect format.)
So I was on Kitpvp and Squill_ was "Selling his Optifine Cape" for 2k. He gave the cape then I paid him 2k and he took the cape back.. As I said I don't have much proof, I'm pretty much hoping you have seen this before and understand.

 

We need in game proof of the deal that was made. I will give you 24 hours to post the evidence. If not, then I will have to close it due to lack of evidence.

 

Thank you for the report.
Unfortunately the evidence provided is insufficient.
Should you gain more evidence in the future, do not hesitate to report this player(s) again.

Kind regards,
The Staff