Well to be fair to them, I think their benefits card provider is a white labeled product from the neolithic era.[0]
Normally I'd say no excuses, but it seems like this was a regulatory necessity if they wanted to provide benefits cards at all. I'm a founder as well, so I can understand the need to provide a significant feature in the short term, even if it sucks a bit.
Being a founder (especially in compliance) I think you could be a bit more forgiving on your stance. A bad experience with a third party benefits card sucks, but saying they "completely fucked you over" feels fairly extreme - especially if your payroll has otherwise been running smooth.