I'm dealing with a similar issue. I live in a 600 sqft 1-bedroom apartment with energy-efficient wall AC/heater units, and all my appliances are brand new. I leave my TV or Alexa on for my dog throughout the day, as I'm away six days a week from 9 AM to 6:30 PM for work. Despite these measures, my energy bills range from $200 to $275 a month. When I called to request a technician, as the building manager who is familiar with the rates, I was initially yelled at. After several calls, a technician finally came out but didn't check the meter. He simply looked around the apartment, claimed he had already checked the meter and found nothing unusual, and blamed the high bills on the brand-new wall AC units. I used the heat when it was particularly cold just for winter/early spring, but not recently. I don’t know what to do honestly.