Stay away from Kingsdown- not worth it

Have had mattress 17 months and already sags. I wake up with a headache and back ache every morning because the bed feels like the cushion moves around. This bed makes me feel like I'm upside down and the blood is rushing to the top of my head. I have turned the bed because it can't be flipped over; only rotated from top headboard to bottom headboard. Going through warranty now and am very discouraged by the negative feedback I've seen thus far. Per Kingsdown, service personnel can't lay on bed and can only take pictures. I believe if it were allowed that they could actually lay on bed that it would allow them to understand the many complaints they are receiving. It seems like this company is ok taking your money but not willing to stand behind their product. Buyer beware!!!!!