Disappointing customer service

My aged parents bought a Simmon's mattress just over 2 years ago, only to find that the bed started to sag in the middle, making it incredibly uncomfortable for them to sleep on. My dad is 70kg while my mom is just 66kg, so it's highly unlikely the problems arose due to limits being tested. They decided to go with a quality brand knowing that if there were any faults, a good brand would have rectified the issue with no fuss, which is why we were surprise to find that this was not the case when my parents notified Simmon's of the issue and were asked to pay R4,400 to have the mattress replaced. I don't consider this the type of service I would expect from a quality brand.