I’ve never given God an ultimatum, but I have reminded him of what he promised.
Most recent example was just this last month. We’ve been struggling financially for some time now, and this month was hard because it was nearly a week after rent was due, and we were $180 short, not to mention groceries, toilet paper, etc…
I prayed a rosary and at each decade, I prayed to God and reminded Him that He promised that for those who seek first His Kingdom and righteousness, he would provide what they need (Matthew 6, I think). I told Him that I believed Him, that He knew my heart, that He knew that my first desire was holiness, and that I needed $300 to buy the things I needed.
Two days later we had a check for $2,000. He outdid Himself.

(Shout-out to the Blessed Queen for advocating for me there, too!)
Anyways, like I said, it wasn’t an ultimatum, just reminding Him what He promised and asking for that promise as soon as possible.