can you “flip” a pillowtop mattress when there are indentations where we sleep?

We have an expensive king size pillowtop mattress. Simmons Beauty Rest. It is only 7 yrs. old and has indentations where we sleep. It is very uncomfortable since these “holes” make it impossible to turn over in your sleep and there is a high spot in the center of the bed. We are trying to figure out what to do. We have 2 other mattresses in our guest rooms that are very old and do not have pillowtopsthey are still quite comfortable to sleep on. I think that the pillowtop “feature” is the problem,but it is very difficult to find a non-pillowtop mattress. We do not want a memory foam one either. Which companies make a regular mattress.