I do agree that this is an issue but I don't think many of these proposed solutions are the way forwards.
I absolutely agree with everyone saying to pay extra for someone more trustworthy, whilst it's not always going to avoid any issues, it'll certainly reduce them.
I think some additional requirements for servicing is the only feasible way to discourage scammers. It'd have to be an automated system as to not put too much extra work on the staff, whilst still being substantial enough to actually make a difference. Maybe like a sponsor type rank you can buy in the store called servicer that acts as a deposit but you can get it back after a week or so of applying for it back? Maybe you get 90% of it back, just so the OSBot staff get something out of it? Just my thoughts