Sudden decay after 1 year

For the first year that I had this mattress, it was fine and was comfortable. However, suddenly after one year, a huge dent appeared in the spot that I usually get on the bed, and shortly after that the springs began poking through and becoming painful to sleep on. I never had back pain before this mattress. Now I have back pain all the time from sleeping on this mattress. If you want a short-term mattress, go ahead and buy this. But if you want your mattress to last longer than a year, go elsewhere.