Sagging bed set

On the 01/09/2020 I bought a queen size bed set from UFO Nelspruit a month later I noticed that the bed is sagging its like there is a big whole on the one side on Saturday the 10th of October 2020my husband went to the store to collect the plasma stand we bought from the same shop and he reported the matter to the salesperson, and she told him she will log a complain on Monday. Monday morning she called and tells the store manager is refusing to exchange the bed for us. I then phone the store and spoke to the store manager and he was very rude to say the least and he told me he is not going to exchange the bed set citing it's government law due to covid 19 and I asked him what am I supposed to do with the sagging bed he told he doesn't know and doesn't care even if I can take the store to consumer council, l now demand my full refund from the store because it means UFO Furniture knowingly sold me a damaged bed. I know my rights as a consumer, l am taking the matter up. I did sent an email to their complaints department still no answer.