Advice about a questionable startup

I was asked to help a group that is developing software/hardware for the blind community. I vetted their legal paperwork, rewrote it, got them their first investor funding, and introduced+organized with nonprofits, universities, medical centers, and industry contacts (none of which they had). I set my own projects aside in exchange for an agreed amount for 1-2 months. I only managed to have them meet with the blind community on 1 occasion and they avoided others. They also avoided many of the other contacts and ignored them. Shortly after they cashed their first check, they split, didn't compensate me for the time I'd set my own project aside, I had to smooth things over with the owner/investor they had been staying with, and they appear to have ignored many of the groups that I'd had them talk to, testing, and further talks I'd put in place. As it turns out, they are back at it again. How should I deal with this group? I'm somewhat tormented by the fact that I recommended them to a number of parties in the disabled community that have been taken advantage of in the past. And, I worry that this company will continue doing pretty much the same thing.