It looks like you may still have a Nest Aware (1st Gen) subscription, which had different pricing for 1, 2, or 3 Nest cameras and separate pricing for 5-day, 10-day, or 30-day video history. If you go to Settings | Nest Aware in the Google Nest app for your camera, it should show what subscription you have.
You can also check here: https://store.google.com/subscriptions?hl=en-US
I don't know whether you can change a 1st Gen Nest Aware subscription; I know you can't add them anymore. Even if you could change your plan, there's no way to get more history retroactively. Here's what you get for each subscription level:
I apologize for my late response and thank you for all of your patience while waiting for a reply. I definitely understand how frustrating your situation must be, and I wanted to make sure that your concern was acknowledged. Do you still need help with this issue? I know that there's been a delay in response since you posted.
Please let me know if you need further assistance.
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