Worst service ever

We opened up an account at the Lewis store in symphony way town centre mitchells plain in January 2018 and purchase a dufy twin tub washing machine the sales person who assisted us was amazing, she even convinced us to take out insurance for it. Then 4 months down the line the spinner stopped working, 2 weeks later they fixed it, then a week later the entire washing machine stopped working, we asked for a new washing machine seeing that we are paying for insurance and the washing machine is not even a year old they choose not to give us one, a month later they fixed it. Low and behold 3 months later the washing machine is broken again the account is more in credit with R1700 and they still refuse to replace the washing machine. This is the worst service I have ever received, we keep getting told that they can do anything we have to wait on insurance, we do we have to wait on insurance it the machine is still under warranty /guarantee we pay the account on time if not before. Can someone please help as we are paying customer and get treated like we do not pay the account, how are we expected to doing washing now!