Lol, this is exactly what I was referring to! We were negotiating a massive renewal (50x budget IN EARNEST!) and out of nowhere they threatened to cut us off with less than 24 hours notice because we were a week behind their schedule, despite signed agreements. Thankfully our VAR (a longtime partner) jumped in and cut a PO to vouch for us and our word.
NONE of our other vendors have EVER done that shit in my entire career. EVER. My word means nothing to them; they act like a pure private equity player now.