There have been a number of topics on this so you might want to try using the search feature to see what has worked for everyone.
Soaking your mat in water either in the bathtub overnight or laying wet cloths on it for a time has led to an almost new mat. Some have had amazing results so please use the search to see what could possibly help you. Some have even been able to save warped mats.
I can tell you my big one that receives the most use has lasted me 20+ years and my other sizes are lasting as well.