Consumer Redressal

Respected Sir, I brought a King Size bed from Om Furniture Interior and Decorators Dhankawadi, Pune on 23 June 2021 along with a mattress worth INR 5800/-. Both were promptly delivered. The bed is of good quality, but the mattress is extremely poor. Immediately within 3-4 days it lost shape and firmness. I complained to the vendor, and after a lot of arguing and haggling he agreed to replace it. After more than a month, he did some basic adjustments to the mattress and gave it to me. But after another week or so of using it, it again lost it's shape and has become unusable. I cannot sleep on the bed for which I paid so much and am suffering from severe backache for past several days because of it. I am requesting the vendor for a refund but he is refusing it. Kindly advise how to redress this situation. Thanks!