Mattress Giant They took my money and gave me a product that hurts my back !!! Wilmington Delaware

I had a warranty exchange from a mattress that was falling apart that I bought originally at Mattress Giant. I was sold a mattress that was so soft that I literally felt I was in a sling (this after the store salesman said it was the firmest that they had , Sealy). I couldn't rest in it and started to sleep on the floor to get my rest and save my back from hurting. I managed (after much arguing) to get it exchanged for what the manager said NOW was the firmest they had....a Serta mattress that they said would work better for me. Even though my original mattress was listed for 400.00 more than the resplacement mattress.....they charged me an additional 400.00 on top of what i originally paid. I now am left with a mattress that is like a brick that i can not sleep on. It is a nightmare. I went to the store after a week and told them that they mattress they gave me in exchange was so hard I could not sleep on it. Basically they said they would call me back (never did). I called repeatedly. finally after a month a lady called me to tell me that she could not get an exchange for this mattress. Now i am left with something i can't use and that I paid way to much money for. I am disabled and I told them this. They acted like they could care less. It is nightmare....totally. I am not sure what to do. I will probably file a small claims case. I don't understand why they would treat people like this.

Myke
Wilmington, Delaware
U.S.A.