Australian embassy Visa application problems

Me and my wife (70+ years) app**** for a visa to Australia via their IMMI facility.We did it 2 times previously and I really thought it to be efficient. During March 2019 we app**** again and paid the 2xAU$140.00 to visit our children in Perth for the 4th time. By 25 April'19 I inquired about the progress and if anything else is needed and received a semi automated answer that the processing is in progress and they are still in their time of assessment. Day before yesterday 22 May'19 I receive a letter from embassy telling me that the visa has been refused. The reasons were in complicated legal jargon, but I gathered it was refused because we did not respond within 14 days of a letter send to us on 13 April'19. I did not receive a letter (SA POST OFFICE service - The Aus Embassy IN SOUTH AFRICA should know the appalling SA Post Office service!!) Why did the Embassy did not inform me via e-mail, is beyond me and in my mind very short sighted or totally uninformed about our Postal Services efficiency. Anyway,I brought the above under their attention asking civilly to explain in plain English what is needed for the Visa approval. Again I received a semi automated answer informing me to check the complicated jargon in the refusal letter. I tried to contact the Pretoria Embassy by phone. Automated voice tell me if I inquire about visas I must visit their website. So I contacted my son in Australia to inform him that I cannot come because I cannot obtain a visa for reasons I do not know and has paid R3000.00 for the 2 Visas which appeared to be swallowed by the Embassy. He came back and informed me that the Australian Government now require "Bio-metric" information for the Visa. Well, I was there 3 times. Twice app**** for our own visas without hazels. -now this nonsense and they do not even tell me about the added requirements. Over and above this secrecy, they claimed to have send me a letter VIA POST not having the audacity to copy the letter and send me a copied mail or JUST INFORM ME that a letter has been send needed more information. Me and my wife are retired. My Visa cost appears to be down the drain, I inquire via email one(1) day before the "lost SA Postal letter" expired and got an answer the very next day -all is OK, we still consider your application! Now.If this is not an example of ineffective customer service of the Australian Embassy, or a form of "disguised" collection of Visa fees,please tell me what it is? I have all evidence of the above statement and swear all above is true and in context of the events. I address this to you because I cannot Call the Embassy about the problem and my mails are answered by semi automated answers. Johan de Wet