Customers complaining about the size of a particular product that’s standard everywhere?

I’ve been running a toy shop on Amazon for the last few months and started off selling Disney style toy cars, think Hot Wheels size.

They’ve been our best selling product so far and been selling on a mixture of FBM and FBA.

But I’d say for approximately every 20 of these we sell, we get a customer complaint that “this toy is too small, it literally fits in my hand!” Or “is it supposed to be this small?” When it states on the listing the size of every product.

With FBM especially, I’m at a bit of a loss with some of these returns, as I don’t charge postage, but end up paying for the postage and the return postage too.

It’s becoming incredibly frustrating, especially when the dimensions are in the listing. What can I do to try and prevent this?