i added 10$ as credits and it says here i used only 3$ but it also says my credits are depleted where did the rest of my tokens/credits go?
The “Cost Estimation” section is a localised calculator for that specific chat session or API payload. It is telling you: “If you were to duplicate this exact request right now using a Pay-As-You-Go API key, this is what this single run would cost you.” It does not check whether you actually have that money available in your wallet; it just calculates the raw token math based on the model’s current pricing.
The red banner at the bottom (“Your prepay credits are depleted”) reflects your actual Google Cloud/AI Studio billing wallet.