Inferior quality of goods and service

I bought a R17 000 couch set. The one seat started sagging and if you sit you fall into the centre of the couch. I phoned and send the couch back in terms of the Warranty in the first week of December. The lady confirmed the supplier is open. After 3weeks she phones and said the couches are back but it was not repaired. She asked if she can keep them and send them back in Jan when the supplier opens 5Jan. I said that is fine. 3weeks later she phoned and said the couches are ready can they deliver 24Jan. I said it is fine. When they delivered the couch it was still broken after being send for repairs on the Warranty twice. I phoned her the same day and said they must come and collect their couches as I do not want them any more as it is of an inferior quality and when they are send for repair the cant even get that right. I heard nothing back from her so I phoned during the next week and she said she is waiting for her manager. After almost another week of not hearing anything I phoned again and she is still waiting for her manager. It is 2weeks after telling her to arrange for the couches to be picked up as I do not want them and more than 2months after sending them in for repair