@dokidoki The whole point of the guild request system is a counter to those scams:
1. request and reward are taken to the guild
2. guild holds the reward and dispatches adventurers
3. on completion, adventurer claim their reward from the guild.
Adventurer goes into request knowing the reward is already put up and the requester knows the money isn't going anywhere until the request is fulfilled.
The village being dumb and desperate went outside the guild system giving money directly to people claiming to be adventurers, so nothing the guild can really do about it. The guild doesn't know who the scammers are (any name they gave could be fake), and the reward was never in the guilds hands so can't expect them to pay back something they aren't responsible for.