Hi twoirrisistable,
Thanks for your comments and feedback and I’m sorry to hear that your mattress isn’t working out well for you.
Unfortunately this is all too common with major brand mattresses that tend to use lower quality materials in their mattresses that can soften or break down relatively quickly (see the guidelines here).
There are some suggestions in post #4 here that may be helpful for a mattress that has developed soft spots or is sagging (virtual or visible impressions) but the impressions deep enough to qualify for warranty replacement.
Phoenix