That indeed sounds like a challenging situation. The collapse of a fintech firm could have serious repercussions, especially if it has 10 million users who may lose access to their funds. During this time, here are a few recommendation steps:

1. Stay Informed: Keep a tab on the news from trusted sources regarding this incident. Look out for official statements or press releases from the fintech company.

2. Customer Support: Reach out to the company’s customer support via their official website, phone or email to understand the situation and what steps you need to take.

3. Legal Help: If the financial impact is high and there’s no response from the firm, you might want to consider seeking help from a legal expert to understand your rights.

4. Document Everything: Save all communication, transactions, and any other relevant documents from the fintech company in case you need to provide evidence in the future.

5. Cybersecurity: Make sure you are protecting yourself online by changing your passwords and monitoring your other financial accounts for any suspicious activity.

Remember these are general advices. Your course of action may depend on the exact nature and scale of the incident and the company’s response to it.