I'm in the same boat as many here: made payments that are taking too long.
I'm not really mad: the support personnel at Plastiq are being as nice and responsive as I could hope. They've offered to cancel my payments and refund my cards if I want - but I really don't want to do that - I want to use their service!
Point is: they aren't disappearing and hiding. They're upfront and they respond quickly to emails.