Groupon Shorted me a box spring, fighting with them to give me what I paid for

I purchased a cali King set through their website. Unfortunately I didn't receive both box spring mattresses that go with this. They do not have a phone number to contact.

I've been emailing them for a few weeks now going in circles. My driver logged that the mattress was short, but they keep saying nothing was logged. I literally have this mattress set that I can not use without this box springs.

I would never order from them again, and will keep fighting until I get my box spring.