1) It looks like you are reporting the wrong person (the one being impersonated by a scammer).
and check accounts for _both_ your canceled and accepted offers.
2) There is no way to get your item back.
3) The way you were scammed suggests that your account is under scammer's control,
and the scammer canceled your offer and created a new one just as you were about to confirm.
Read these blog entires (except in your case it wasn't a deposit)