Wur ta mrs? Fis goy iz n idot!$@
You sold it as an ion threaded barrel, he bought its as described, did you have a return policy?
If not, tough darts for him, he screwed up by not paying attention.
If you did, try to explain what i just said that you listed it as this ( ion ) thread and he should have known if he needed otherwise because of his "experience".
I hate people like this, I feel for you.