Sold me a broken bed

I bought a bed October last year from Margate Store within one week we realize that the bed is making noise. I contacted the the branch, the lady said the bed will be replaced they will contact the supplier. Every time I call she tells me about the supplier. I have also contacted the their head office several times, they always say they will get back to me. Mattress is of poor quality, now it sinking in, it is now shaped like a boat. The bed has not finished 4 months. These people they don't take their customer serious. Please attend to my complain.