Poor quality products but deny responsibility

I had no feedback on my previous complaint regarding the absolute ******* I bought from Rochester. I bought a Restonic bed and base from them and not long before the bed started looking like something made of s****s. Eventually Restonic agreed to replace the mattress IF I was willing to pay R1750 !! Which I did. The replaced the mattress on August 2017 and November the mattress started sagging AGAIN! After numerous attempts and complaints nothing is being done. Management are just passing the buck and I struggle with back ache due to the poor quality of the mattress, talking about “Quality “ you can relay on!! I’m prepared to take the issue to the media and social media even ombudsman if I have to but Restonic think they can treat customers like ******* and own the monopoly