Kids Adjustable Quad Roller Skates

I purchased this skate for my son even though it's purple, he doesn't care. He wears a size 11-12 in crocs kids shoes so I thought this would be perfect and he has a lot of time to get to size 4, which is the max listed on the size medium we purchased. I was under the impression that was equivalent to the J11-12 in small, I guess. When we received them and he tried it on, he said they were tight. I took the shoe out of the skate and his toe touches the top of the shoe and it certainly looked tight. I extended that adjustable flap at the front so his toes have more space. But I actually had to also pull out the skate to where it adjusts to a size 3 so that he felt comfortable. He now has plenty of room in the skate itself and I can see how that allows more room. But the interior shoe is still very small and tight at the toe area and he says the material digs in to his feet. It doesn't look like any way to expand the material around the toes either. I will be returning this and looking for a larger size because I don't think this will last him as long as we had hoped. Also the rubber stop on one side looks already scratched and he only tried it on in the house. He doesn't even know how to skate yet.