Worst (& most expensive) decision I’ve made

I have been so incredibly disappointed in this mattress. When I tested it out at Mattress Firm I absolutely LOVED it. It felt soft & bouncy but very sturdy and well made. I decided to splurge because I have a chronic issue with my neck since an injury a few years ago. My current bed did me no favors so I thought I was really upgrading. I did a tremendous amount of thinking and online research but felt like it was impossible to trust both good or bad reviews because I read so many of either. I also trusted the Mattress Firm policy. I really regret that. I knew right away that this Mattress did not feel like the one in the store. I tried to figure out why by going back to the store but they blew me off saying it needed to break in. A year later I am miserable every night. My mid and lower back hurt so bad at night and I never get comfortable. It’s the worst Mattress I’ve ever slept in. And it was by far the most expensive at the store. So I couldn’t even trade for a comparable Mattress from another brand. The salesman just never answered my attempts at resolving the problem. This is a nightmare Mattress.