Well I got a phone call from the Optus complaints team. And believe it or not the manager agreed with my reason for complaining and has compensated me ( credited ) for approx 14 months that I was paying for the 50/25 that I could never achieve. He worked it out that I was on the $90 BigBundle and has credited me the extra cost of the 100/40 speed pack even though I was only on 50/25.
So I am quite happy with the outcome. He even offered to put me on the 100Mbps plan as he said that the micro node I am on that I could achieve about 80Mbps.. but recommended I stay on 50Mbps...which I am doing.
So all in all a very good outcome.