Bad Service

We originally bought a bed "the Sealy Hybrid Sage Firm Mattress - Queen XL" but over the last month of sleeping on the bed we feel its way to soft, the specification for this bed is suppose to be firm, but it's so soft my body feels sore in the morning, so we contacted The Mattress Warehouse Randburg to exchange the bed for a better one, however we are getting no response from them, my wife has phoned them more than 3 times and they keep telling us someone will contact us back, but no one does. She has been speaking to to a "LJ"