Second hand device sell but mobile was faulty and had issue within 48 hours.

I purchased a Samsung Fold 4 from Hakimi Second Sale on 13 October 2026. Within 48 hours of purchase, the front display stopped working, and after that the inner display also stopped working. The phone was never dropped or mishandled in any way. When I approached the seller about this issue, they denied responsibility. At the time of purchase, they had verbally assured me of a 15-day guarantee, but when I went back to claim it for the display issue, they refused, saying there is no guarantee on the display. I request that the seller honour the guarantee promised at the time of sale and either repair the defective displays free of cost or provide a replacement or refund for the defective phone.