Hills and valleys

We purchased this mattress along with a new bedroom suite about two years ago. We had the first mattress replaced within days of receiving it as it felt like we were sleeping downhill. The new mattress was great for a few weeks but within six months had developed body impressions that didn't go away. We always rotate the mattress a quarter turn so it will wear as evenly as possible. Now the impressions are so bad our sleep is suffering and we are shopping for something new, something not made by Sealy. We had trust in this company. Money down the drain.