Sagging mattress

Have had this mattress warrantied multiple times. It is a waste of your money, my inlaws had the same mattress we bought at the same time. They had theirs warrantied 4 times before discarding it and buying a different mattress. Ours is good for six months then it sags. They come out and measure and give us a new one, I sleep in the same spot on my side every night, mattress just won't hold up, my wife weighs 102 lbs and her side sags too. (More than 1")