Poor product & poor after sales....

I bought an bed at the bed shop in Kathu in June 2018.....After 2months the matress started to disformed....I did contact them newmeros times.they send some to come and inspect the bed,they couldn't help me. they told me they cant refund the bed.their sales rep must come and see the bed to make an descion.......They said he will come end off october....we are now in almost middle january....still no respons from them.The bed is realy making my back sore....The bed is still under warranty.I realy don't know which way from here.....