Paid R159,99 have slip but no refund

I bought headset during mid October fron CNA Sandton and they are now broken. The CNA Sandton branch is closed for renovations so I went to the CNA calton center branch which is on my way home to return the headset, I still have the original packaging and purchase slip, but the store staff and manager told me that this iterm had no warranty. This is something that they should have told me when purchased the Genius headsets so I had the choice to save my money. This is the second headsets as the first one also broke in a similar way only a week after purchase and I returned those and got this set of Genius headsets. R159,90 and the product is on good for a month. I bought the headsets at CNA hoping to get a better quality and durable product, before Christmas the bad headsets sold a CNA have broken.