Kurl-On — Replacement of defective mattress

Hi, We had purchased a kurlon DC matress from fabfurnish site in Nov 2015. Soon it started to sag and we reported a complaint in March 2016. Techinician visited and confirmed the defect in mattress and recommended a replacement. Since then, it is around 3 months and we have not yet received any repalcement, also no formal notification is received regarding replacement of the same. Everytime we contact customer care, we are told that we will receive it in one week and it never happens.