Amazon's Wrong-Size Delivery and Frustrating Return Process

I got the wrong size of a product I ordered from Amazon. I started the process for returning the item and sent it back, but the refund hasn't been made yet. The package was sent to me instead of being marked as a return, according to the tracking information. I couldn't find anyone to talk to because there wasn't a customer service rep around. I lost both the product and my money, and I'm the one who has to pay for their mistake. I had a lot of hopes for Amazon, but it turned out to be a huge disappointment for me. I need a refund right away. Please give it to me as soon as possible. Thank you.