It’s probably too late to do anything about it, but what you described there does directly violate Indiegogo’s TOS in regards to perks, so I’m surprised that people weren’t able to reach out to the platform itself and issue chargebacks against the Creator in order to get their backers payments back.

They are actually obligated under the campaign owner obligations that in the case they can’t fulfill a perk, they are supposed to issue refunds to any contributor that was not fulfilled