Bests & Worsts Reviews from Amazon

I bought this mattress about 1 year ago and it is sinking...horribly. First, I had to pay $35 for Serta to come out and inspect my mattress. I qualified for the mattress replacement; however, I had to call for everything because they never got back to me. When they did, I found out I had to pay over $150 dollars for the delivery of the new mattress...paying almost $200 for my warrenty that they call "best customer care warranty" is unfair and a bad way to keep customers loyal. I wont be buying a Serta again.