I’m not sure what any of this has to do with Google charging the full amount despite these people being on payment plans. It wouldn't be acceptable for any other provider to do this and it isn't acceptable for Google. The state of these peoples' finances makes this worse, and doesn't absolve Google. It's incredible the mental gymnastics well-off people will do to shift the blame to the poor instead of the weak, vulnerable billion dollar enterprises that fuck up.
This guy took the payment plan according to what he thought was able to pay monthly. And until Google charged him $1000 out of nowhere, that was fine. That's all there is to it.