I've don't think I've ever not paid anyone what I've promised/agreed.
Which means that sometimes I don't promise much, but I'd rather people knew upfront what they stood to get from a gig.
Is not your money to hold back. If you make a loss, you make a loss.

I've taken less money from playing, if I know the promoters and know they are suffering. But then at least its my decision to waive, not theirs to not pay me.

I'd say you have every bloody reason to be angry.