Autumn/spring waterproof boots

We bought them in the fall, but the cold set in so quickly that we didn't get a chance to wear them, and now they are already too small for the child. The shoes are waterproof, lightweight, and easy to put on; they come with a receipt and a valid warranty. One minor issue is visible in the photo: the string at the back is slightly frayed, but it can be cut off as it doesn't affect wearing at all, more like a decoration.