The moment you pay them, you're endorsing it. Sure, make your public "whoops" statements, but at the end of the day, it's your fault for hiring them and you get the rep hit as well.

I think this is a case where it's justified to consider them guilty until proven innocent. Interacting with customers is what they paid these guys to do. It's not like he's doing this in his spare time or anything. Yeah, they probably don't endorse it, but as has been pointed out elsethread, this isn't the first time this awful marketing company pissed people off. When it comes to Googling for due diligence, surely the same applies to choosing your marketing company.