https://www.cashrewards.com.au/store/energyaustralia
When I signed up for Energy Australia's electricity, I remember the Cashrewards website listed a cashback offer around $17x at the end of July, but now it shows $105 and this is what they honor.
Cashrewards has asked me to provide proof, such as a screenshot.
I checked the Wayback Machine at https://web.archive.org/, but I couldn't find the information there. Do you have any suggestions for another way to obtain this proof?
I'm not sure if Cashrewards will accept this as proof, but you can see the history here: https://www.ozbargain.com.au/deals/energyaustralia.com.au
What date did you sign up? It changed to $105 on the 29th July.