ONLINE wrong item delivery

I am writing to express my dissatisfaction with the ongoing issue regarding my recent order. I ordered a cake stand in a specific size, but upon receiving it, the wrong size was delivered. I promptly requested the correct item, and the cake stand was picked up by your team 7Feb (3 weeks after the wrong one was delivered). However, when I spoke with a customer service representative, I was informed that it would be easier for you to issue a refund instead of processing a replacement order. Since that conversation, I have been waiting for my refund, but despite multiple follow-up inquiries, I continue to be told that the matter is "being processed by the seller." I am extremely frustrated with the lack of progress and clarity on this matter. As a customer, I expect to receive a timely resolution, and it has now been more than a month since the return was made.(Not even talking about the time the order was placed to begin with).