Hello JackThePhantom!
At the moment, you can't really do much about a Fake Voucher because it's basically claims as just a Player Head but you may report it through
Link.
I am sure maybe something can be fixed about this or Claim Blocks may just get disabled again if too many reports arise because of these new Fake ClaimBlocks Vouchers but their not much we can do as a Player to fix.
Sorry that their isn't much information that we can Provide at the moment but I am sure in the near future. something will be fixed/changed about these.
Thank you,