faulty product no refund

I bought a double bed from OK furniture in Parys on 22/12/2017. The bed is a "Dreamzone" and cost R3999 on offer. The bed is less than 3 months old and is only used occasionally (every weekend). The bed was firm when bought but is now very flimsy and wobbly, you can feel the springs poking out and it has a dip in one side. I don't think this is acceptable after 3 months!!

I went to OK furniture today and explained the situation and took along my receipt. The manager told me that I will need to have the bed replaced 3 times by the supplier before a refund can be given, not only that but it will take 1 month to replace the bed!! This bed is for a guest house and is needed. I find this totally unacceptable.