Sinking bed

I bought a bed and it's a titanic, springs are out I even put blankets underneath. When I went in store to complain 2 weeks back the consultant said my bed was made for kids not for me. I feel I was mislead and not treated fairly when I bought the bed, the salesman just wanted to push his sales. I complained 2 weeks back even now you guys still can't find my invoice number after I submitted all my purchase documents