Sleepmasters sell inferior mattrasses

I bought a mattrass from sleepmasters thinkig that they will deliver the same quality product. However, to my surprise Sleepmasters delivered an inferior product. The shop and their service agents are refusing to exchange the mattrass because I didn't buy a sheet protector. Why must I buy a sheet protector if I have plenty in my house. This is a day light *******, and I believe I cannot be the only one complaining about Sleepmasters. Please stay away from Sleepmasters.