Question with selling apps, and refunds

I've published free apps but I'm new to selling apps.

I've had people request refunds after buying my apps, and it looks like Google just automatically refunds them money without me having any say.

So now I want to sell an app but it's seasonal and does 1 thing (although pretty well, based on initial tests). Can anyone request a refund for any reason? I just don't want to put this seasonal app for sale, and then everyone requests refunds the day after.