https://i.imgur.com/Xq27eYg.png
https://i.imgur.com/X8oYaFL.png
Basically trying to justify scamming because the other party was being rude/impatient.
okkk..
I would advise you to file a detailed report and include any screenshots and trading history on steam on steamrep forums. I would do this but unfortunately this is your case and you must submit it. This person has scammed others before and somehow got away with it and still is not banned on steamrep.
Here is his profile on steamrep: https://steamrep.com/profiles/76561198043968904
Report the scam by opening a thread here on steamrep forums: http://forums.steamrep.com/forums/report/
Include all details you can provide to have a higher chance of getting this guy banned for good.