Wow Molly that is weird, you maybe need to change supplier or ask them to check/change meters. I have always found BG customer service to be good.
We have an extended 4 bed house, 4 in house including 2 teens although DS going into second year at uni. But when they are at home they have laptops, TV on a lot. Not to mention charging eleventy billion devices! We have a woodburner in kitchen but heating on in rest of house in winter.
Pay £119/Month for both, split about 70 gas/50 electric. Seems high compared to some here, but low compared to others. I am only out two days, work at home one, so there are at least 5 with someone here, and we usually have laptops, main PC etc on, washer average once a day, dishwasher once but twice when both kids are in and eating constantly! We cook with gas and do like roasts and casseroles so use oven a lot.
I do have times when I think we should be more careful but we are careful in so many other ways, so can easily afford what we pay, and I hated as a teen that my dad was always switching the heating off, esp in depths of winter in cold Yorkshire, so try not to be that parent now! And I am sure our bills will drop significantly when kids no longer at home!