This Bed appears to give out after 2 years of use...

We bought this bed from Sleepy's (now Mattress Firm) May of 2016. We needed a new bed that was going to work better for both of us. Our Adjustable Air bed was just not working for us, and we decided to finally go to a mattress store. We moved into a new house, and thought new beginning. So we sprung for the Simmons PHENOM CROSSOVER PL/FM QN MAT after spending a lot of time trying out mattresses. We believed the sales person (who apparently was a trainee under the guidance of another woman) sold us this mattress (which according to her was the closest to the one we tried out. It was comfortable and we felt the body relax and slowly sink into the mattress. I felt like my back was supported as well as my hips. I have back issues and really needed the support. This one that she sold us felt amazing. So much so that in the store both my hubby and I were so relaxed I could have fallen asleep. We ended up buying the adjustable base because it was great to have the option to raise the head, have the massage option etc. Well, about 6 months ago it seemed as if the springs got really noisy. Just sitting on the bed made a lot of noise. The mattress itself, once really firm when you got on it and then sunk in, no longer happens. It just sinks in. The sides don't hold up either. Its like the bed "loosened up" and lost the firmness to hold people up. I can't sleep and am up several times in the middle of the night with back and hip pain. It is NOT the same bed that I purchased and after spending so much on a mattress I am frustrated beyond belief. Both my hubby and I feel the difference and have commented many times that something is just not right. After this experience, I would be less inclined to step foot in a mattress store ever again. I'm really disappointed in the makeup of this mattress and will be filing a warranty claim on it. I'm going to guess that nothing will be done however, as the feel is what the problem is and no picture can show that.