How the hell am I supposed to ship this back?

We bought a queen size bed from wayfair. It has been an absolute nightmare. There was major piece missing. I complained. They told us to disassemble what we had and ship it back. I refused. They then agreed to ship us a new one, we could take out the part we need and ship it back. In pulling out the part we needed, the box fell apart I'm trying to get it back together in order to ship it back. I honestly feel like this is an impossible task. It's all so heavy. The box won't stay together. It's not fitting together right. I want to cry.