Guys, after purchasing 2 mattresses in just over 5 years, really need some help/advice. New mattress July 2017 lasted only 9 months before we noticed a well developing on both sides of the bed, with a distinct firm ridge forming in the center. Mattress is turned regularly, not turned over as it has a memory foam topper built in. In short, bed retailer & bed manufacturer don't want to know. Its got so bad, that now we are sleeping in the spare room, that has an old style mattress. So, what have you got, & how happy are you with it.