Is it on? How long do you have it on, and what temperature?
I've turned mine on to come on a timer for 2.5 hours in the morning and 3 hours in the evening at 18c. Maybe that's a lot but I'm home most of the day and I feel the cold, plus the morning heating keeps the house warm most of the day. Last year I had it on for only a few hours at 15c and it was miserable. I have a nice amount of credit in the energy account so I'll see how November goes.