That's just ridiculous. From what I've read it looked like campaign manager was trying to WARN you and not BLACKMAIL. You've made a fuss, what do you think campaign manager would look like, if he paid you after all those posts you've made within a short period of time? You should've thanked him that he was worried about getting you your payment in the first place. Needless to say on BTT in campaigns with high payment managers are strict and it's a normal situation when you make a qualifying number of posts and still not getting paid because manager can consider some of them as nonconstructive. But it's not even that kind of situation now, you were about to get paid!
$960 - where did you get that number anyway? Why are you so confident you would've stayed in this campaign for any longer than 1 or 2 weeks? Any of the participants can be kicked out of the campaign. So what now, each participant should open a scam accusation for not getting potential payment?