Poor customer service

I amazed by this poor service in replacing a mattress for our main bedroom. Firstly this was a bad choice of bed because since the purchase bed gave way so many times and when i called the store i was informed the bed has been discontinued but the mattress was still under warranty and could get replaced. I spoke to Fiona on 29 September 2017 and to date no one has come to assess or replace the mattress. I am going to take legal action. I suffer from scoliosis and if you know what it is then you will understand my fruatrations. My back is ****ing me