how were you 'ripped off' ?
Does your printer work ?

Also have you checked that the rebate was from flashforge and not the people you brought the printer from.

You can't just say: don't buy flashforge because you didn't get a rebate.
Have you used the printer: did it work, did it break, was it any good. These are reasons to have a go at printer manufacturers - not something like a rebate that has nothing to do with the printer's quality or performance.

As a general rule, flashforge are one of the top manufacturers both for quality of the machines and reliability.

Offer is no longer on the B&H website. If I were you I'd read the small print and find out exactly how the rebate is supposed to work.