I have a similar problem. All of a sudden our power bill is estimated at around $750. It’s just me and my wife. We have gas hot water and oven and are mindful around power usage (hanging out washing, don’t use the heater much etc) Get this..I am in Sydney (have been here for 4 days now) I took screen a screen shot of my bill and we’ve mysteriously used almost 200kwh and no body is even home?? Hopefully we can sort it out or I’m out! New provider