Desperate assistance needed

My sister immigrated to Australia ± 25 years ago and has never earned any income in South Africa since then. Last year I received a notification that she needs to submit an eFilling for income tax. Both she and I have been trying to sort this out with SARS but nothing gets resolved. I tried calling many times requesting a call back which never happens, I also decided to keep a record of the amount of times I have requested this. When we speak to an agent it is always different instructions or to upload documents onto a case number and when we do this is says that the case number is closed, when you call back no one knows what you are talking about. I emailed *** explaining my situation only to get a reply that someone would contact me but no one never does. I keep getting a SMS stating that I have to pay a fine for not submitting eFilling. I am phoning them as I don’t have transports during the week to go to their offices. I am desperate to sort this out and not sure what to do anymore.