Kurl-On — Quality of Kurlo Bond mattresses

I have purchased 5 inch kurlo bond mattresses (one pair) in the year 2018 and after using them my wife has been suffered with back pain and severe ribbs pain. It is too hard to use them and get a sound sleep on these mattresses. The warranty for these mattresses are upto 7 years. As these are very much uncomfortable, is there any procedure to replace, return or buy back in the company or we have to bear these uncomfortable, harmful mattresses. I am living in Agra (Uttar Pradesh)
and I had purchased from Kurl-on Dealer of AGRA.