Bad service Mattress warehouse Nelspruit!!!!!!!!!!!!

I bought a Kooi B series queen base set at Mattress warehouse Nelspruit in August 2018. Mid 2019 the mattress started to cave in and I made a complaint with the guy by the name of Kobus in November 2019. Kobus did not get back to me until February 2020, when I asked him he said he cannot find the complaint form I sent and requested that I send him another one. I did that and again he went quiet. August 2020 I called Mattress warehouse Nelspruit and I spoke to Ruth, she said I should send her the complaint form again which I did and she also went quiet. I do not know if this is the way they treat their customers, but I have to say that I am very disappointed at their customer service. To think that I was told that the bed set has a 15 year guarantee, but within a year it was faulty and they haven't replaced it till now. Mattress warehouse please help me or give me back my money!!!!!!!!!!