Mattress Firm did not honor their warranty on my defective product San Diego CA

We purchased a new bed from Mattress Firm in August of 2022 for $2500. They told us then the purchase was under a full warranty. Two years later, there are deep ridges where our bodies lie on the extra firm bed (we are both under 150 pounds).

I called them and they directed me to file a warranty claim on their website, which I did. I uploaded all the photos as requested. Two days later, I got an email from the corporation that this bed wasn't under warranty and I had to file a warranty claim with its manufacturer, Kingsdown. I did. Then I heard back from Kingsdown that this particular bed was made expressly for MF and was under THEIR warranty.

I then refiled my claim. This time, they demanded photos of the bedframe with the box springs removed. I said "we can't lift this" so they suggested we pay $80 for their tech to come and do it (and that $80 would be applied to the delivery cost of the new mattress, which is $100). So now we're up $2580. The tech came and was surprised by the state of the mattress. He said they'd definitely have to replace it.

The next day, the corporate office said "there are stains on the mattress, so we can't honor the warranty". The stains are insignificant, but this is obviously an excuse to not have to replace the mattress - what were they going to do with a defective mattress, sell it? This is deceptive and dishonorable and I would never shop there again. I hope anyone reading this who considers shopping there looks elsewhere.