False Marketing and delivery of inferior product

My contract with Metrofibre started way back 2018/2019 and I recently learned that the 500 Mbps up and down package that was offered can only give me a test speed 90.77 Mbps download and 92.25 Mbps upload which is way far less than my package. I have lodged a complaint with them and no one has bothered to be in contact with my to resolve my complaint. Worst of I have been paying for a package which has not been offered for years. All I want is a replacement of the current router to the one which can cater for my package and the refund for the money that I paid for a service which has not been delivered