Review on 🔲 10 Pack Black Powder Coated Aluminum Fence Post Cap (3 1/2") - Ideal for Mailboxes, Lamp Posts, Decks, Docks, Piling Caps by Chris Russell

This is a very good product but it does not fit our standard 4x4 wooden fence posts. I'm confused as to why they fit in other reviewers' fences (except for one reviewer who noted he had to change posts), but they're too small for ours. I have contacted our fence installer to ask what to do about this but have had no response. It's too late for me to return the product and I don't know what to do in this situation. I've tried contacting the seller but haven't received a response from Heartland Products USA so I'm trying this route. Thanks for any feedback/thoughts on what to do next.