New seller – need advice on what action to take

Hello, so I’m a new seller and I’ve received a negative comment as my first on my store page.

The comment was complaining about being charged twice and demanding a refund.

I tried to look through my orders to match with that person’s name but I didn’t see any sales to that name, so I assume that means they didn’t actually buy anything from me? Can they still leave a comment if they didn’t purchase anything from me?

What should I do now? Can I get some recommendations? Or was I using the wrong method to find the customer in my orders?