I work for a company that has spent billions of dollars on Google ads in the last decade and it doesn't seem like we're a big customer either.

Sorry to break it to you, but you are not a big customer to Google either.

Let's assume that billions is actually 99B. So roughly 10B/yr. This is roughly 4% of their income in a year(~ 284B in 2022).

Big customers are at least double digit % of their income.

Source: trust me bro

Ah-ah. I am sure even if you had millions of $ in support fees, they still won't care about you. You have to have pay more, get a dedicated accounts team and let them manage issues internally.

Millions? That's not even in the right ballpark for them to notice one way or another.

Google brought in around $284B in 2022, Big customers are at least double digits, so for Google, one needs to spend at least ~ 30B/yr to be considered a big customer to them.