King Koil Bed

Hi. I bought a king koil bed for R14000. 00 from furniture city in port Elizabeth. To my disappointment, week later they were having a closing down sale. Everything was half price but I was happy because this bed was suppose to be a good bed. Well, it is not even 6 years later and this mattress sagging, looks like the "Kimberly big hole" . I cannot believe that it didn't even last for 10 years. It is alot of money wasted on what I thought was suppose to be such a good bed. I wish someone would come out to assess. The problem is I don't have my proof of purchase because I keep slips only for 5 years. But I'm sure there should be documentation somewhere on king koil side. This bed has a 10 warrenty. There should be a way that this situation be rectified.