Makro SA online poor after-sale service

I bought a Hoover hand vacuum on Makro online for my mom when she turned 75 late last year. It helps her a lot to keep her room clean. The vacuum suddenly stopped charging and is not working anymore. After numerous attempts, calls and emails, I have yet received an indication from Makro as to how I can exchange this. I have been trying for almost a month, with Customer care promising every week that they will collect the item. I was also told that I can't exchange it at a store.