Deceiving company

I usually do not write reviews however I really thought to do this maybe someone else doesn't go through the health problems that I am going through. I asked to buy a Sealy Elevate Ultra mattress Queen but they gave me an exquisite Sealy and told me it is the same but a better version, Mattress is sinking in the middle. I am just 56 kg, a single girl. It sinks a lot in the middle and the mattress is firm. They do not accept to fix it or return it. They took the mattress for inspection 2 times after I called and e-mails them like 20 times. It took 4 months they take it for inspection. They did nothing and told me it is normal. I have had the worst back pain ever. I started grinding from pain. Couldn't have a night proper sleep. I seriously recommend do not throw your money in the bin and end up with Chiro and physio