Still waiting for a response after 4 days. Starting to feel like a ****.

I ordered a 5 tier shelf with next day delivery. When I got the item and crucial assembly part was missing. I got into contact with support and was told to log a return so I can get a replacement. Monday morning I sent my email. Tuesday morning I got a response asking for photos for proof of missing items. I sent it that morning. Rest of Tuesday went by, Wednesday came and went, and it seems like Thursday is going to be the same. I've sent multiple replies to the first email asking for an update and have not received any response.