And they'll let you roll over $9000 worth of unused credits by purchasing just $1000 new ones? This actually sounds like a pretty good deal.
I think your problem is that you purchased more than you needed via a contract you didn't understand.
Obviously OP made a mistake here, and it seems that they're admitting that, but if what they said was true, this company was being deceptive about the contract.
Based on their website[1], you can have an account with pay as you go. There is no reason to assume that if I change to a month to month agreement, I would have to create a new account. Why shouldn't the rollover minutes stay with the account? OP paid for it already.
To go back to the AT&T analogy, if they offered a prepaid yearly contract with rollover minutes, and I lose those minutes because I switched to month to month, I would be pretty angry.
You pre-paid for $10k of usage, with an agreement to roll-over unused credits into next year's contract. The plain definition of roll-over includes the fact that you'd have an active future account. Otherwise, they'd just say "prepay credits never expire". Imagine trying to use roll-over minutes on a phone plan where you cancelled the phone.
$1k/yr seems like a very low minimum which will serve as basis to roll your $9k of existing credits into.
Sounds to me like you just didn't think about or budget for this. Doesn't sound like any misrepresentation to me.
My post is definitely a lesson learned and shared to others who are small and may be interested in getting better engineering support from Snowflake (a benefit of signing up that was the main reason for us that we ended up not needing) by the contract route to question their sales rep in depth and get it in the contract itself, and honestly, should just stay on demand.