Probably the closest I've ever been to getting a heart attack. Normally <$1 per month, and now suddenly $284,006,266,443.74. Whatever the bug is on their end, this is unforgivable.
I’m also a little surprised this didn’t trip a circuit breaker. For something as non-real-time as billing, I’m surprised they don’t have an automated kill switch that pauses the billing system and fires a page if variance in bills spikes. Naively some kind of “if the standard deviation of customer bills for this year changes by more than 50%, pause the billing system”. At that number of customers, those numbers should be pretty stable beyond internal billing changes they could normalize for.
It's been 2 hours and I still haven't fully calmed down.