There's pretty much no reason to be using more than the tiniest amount of gas at any time but especially since February. It's been a very hot year which should mean minimal/ zero central heating, food that doesn't require cooking, and cold showers. Or at least cool showers given the water from the cold tap is so warm. Our central heating went off in January, we've used one or two hobs on occasions. Our behaviour is much improved since (obviously) early February and our bills (for two adults with very strong appetites) are minimal. Our electricity bill combined with gas comes to about 85 pounds per month. Switch provider or turn it off. Or both.