Hi StillDark,
All I can say to that picture is WOW! What a mess. If the underlying mattress was worn down, the support or foundation was bad or any combination of all of it, nothing was going to save your mattress system. There is no topper that was going to solve that situation. A mattress is only as good as its weakest link. Once one layer goes, that is it for the mattress. Unless it happens to be a comfort layer that can be swapped out.
If you take a look at this article, Luma Sleep Winding Down Operations you will see that they are no longer in business. There website doesnt work either. Unfortunately, the only solution is going to be a new mattress.
If you do some research, if there is any pending litigation or some other brand that took over their operations that will honor warranties, that would be the only hope. Otherwise, sad to say, this one is a loss.
Sorry this has happened during the holiday season, like all other things, there is no good time for an unexpected expense to hit the ledger sheet.
Hopefully, you find a new solution.
All the best and happy holidays
Norm