useless business

My name is Marleyne Mulaudzi I bought a bed at Sleepmaster on the 1st of September after 5 days the mattress was sinking so I called Sleepmaster Clearwater where I purchased it they promised to call me but they never called on the 18th I went to the store they logged a complaint with their Head office on the 20th they asked me to send the pictures of the mattress I send they never say anything until I phone the complaint department again and I was told they would deliver on the 2nd October they never update there's nothing I have been phoning them everyday nothing can you please help me I'm tired to talk to this people I just need my money back since the fail to solve the problem