Returns policy for oversized items

Hey y’all

What is the return policy for mattresses?

I purchased one and it is faulty. I purchased it from the warehouse in the box it is a Simba.

Now the customer service corporate is saying I need to take it back myself for the refund but if I bought this online, they will come and collect it no problem.

I thought Costco could collect as an exception because no way does a big king size mattress fit in my car when I purchased it in a small vacuum packed box.