Bad after sales service

We bought a bunker bed on 28/07/18. It is for a 2 year old and an 11 year old child. after 3 months the children would wake at night and complain about the mattress. We investigated and found that the mattresses were laying hollow and causing the children discomfort. After contacting Decofurn Centurion they said they would have to investigate. We asked where the children have to sleep in the meantime. We were told this is procedure. I phoned the manager to find out what they were going to do, and his response was that he is not aware of the complaint. I gave him the email address to which the complaint was sent. He acknowledged that it was his mail, but denied that he received the complaint. I made copies of the mail and took it to him personally and only then did he say they are investigating. (4 emails were sent). He was very arrogant and insisted that he must follow procedures. This is the worst service we ever had from a furniture outlet ever. Think twice before using them as their service is pathetic.