but you must read point number #8
Rules of Signature Campaign
8: Managers and Owners reserve the rights to apply new rules. change any exist rule or do any other reasonable changes (including payment structure and amount)
Any changes to the rules are allowed only forward, any changes in the rules are inadvertent retroactively.
If you've claimed/joined the bounty with predetermined rules/conditions, and you've completed said conditions then you have earned whatever was *promised* at the time. Changing these conditions afterwards is shady at best / an outright scam.