I wonder if Google does anything to accurately reimburse something like ad-naseum* clicks. I imagine the probably take up a non-insignificant amount of spend at the $6m level
Google automatically refunds advertisers for fraudulent clicks each month. It's not a lot (maybe $1,000 refund on an account that spends $600k to 800k/month), but it's a line item on the invoice for sure. You have to trust them for what is a 'fraudulent' click though.
*https://adnauseam.io/