Poor Quality of couches and assistance

My Granny purchased Red leather couches at beares furniture shop in Butterworth. She then was required to pay R3000 per month for 36 months (3 years). Now I'm quite sad to say that the condition of the couches ,that are barely used at home is extremely poor. We know and understand the shop of its star alliance to quality goods but I'm not at all impressed. My Granny then went to the Butterworth branch to complain and they claimed that there's nothing they can do about it as the couches were purchased 4 years back. I am literally disappointed in the shop