Yours is not an isolated case. There are multiple posts on Reddit from the last few weeks where bedrock quotas were set to 0, even for accounts that were actively using bedrock.

I've only seen it in accounts that weren't actively using bedrock, which is annoying but not business ending.

AWS needs to get on top of this sort of thing before people lose confidence in their platform, but I fear they may have lost too many staff to be able to get it the attention it needs.

It increases based on your spend and account history. Unfortunately to get it to increase, you gotta basically just blow money on other services before they trust you enough to let you use certain expensive services. I would venture to guess people were using temporary credit cards to sign up, then not paying the bill.