we bought a mattress in mar 2004 since then we have had 5 new ones due to sagging and exchanges all we want is one that my husband and myself can sleep in together without having a hump in the middle they say it has to be 1 1/2 inches but without laying on it it doesnt go that far try sleeping in a bed that you can roll over a hump in middle each time we have replaced we have spented more money to get better quality but the same happens each time where do we go from here