There could be clear cut guidelines in place that if you use @buildawhale for something like this, the vote will be pulled and the person doesn't get a refund. If you've already taken money from people that are blacklisted in the past and not returned it, I don't see where expecting you to pull a vote from garbage like this is a stretch. Do you want repeat business that hurts the platform?

edit
For clarification, I'm not trying to single you out here, but most of the other bidbot operators don't really seem to give much of a shit about stuff like this. In the grand scheme of things, I understand the logic that stake weight is essentially being rented and whatever they do with it is going to happen, but I don't think anyone is going to be upset with you if you pull the vote and tell this guy that you don't want his business anymore. If you do want his business and don't give a shit, then don't bother defending yourself on the "It's not my fault he misused a service I offer" comment above. Just my two cents.