Planes from the past

Last month I flew on SAA from New York to Johannesburg. This being an extremely long flight, I expected the plane to be at least half decent but no. The plane was something out of the 90's, my screen was old and faded, my headphones broke almost immediately (due to poor quality) and I couldn't use my own because there was no auxi****y jack and the seat cushions were hard and worn out. This was by far the worst flight I've been on, it's no wonder everybody is choosing their competitors. I was warned against using South African airlines but decided to give it a go. What a colossal waste of my time and energy. Is this the level a large, well known airline should operate at? If it wasn't for a friendly staff member I would have lost my mind. They should bring their company and fleet to this decade.