BekkaJaine: ...This is my first time posting so apologies if I am asking a question to which the answer is obvious....
No, the answer is not obvious, but first since this forum is part of a price comparison service, next time you are looking for energy consider using a price comparison service rather than face to face marketing. In fact start building your confidence by doing some comparisons.
The most important thing is to know what is your annual consumption in kWhrs. If you have been a customer for more than 12 months annual consumption may be on your bill, otherwise ask British Gas what is their annual consumption assumption. Next, from the most recent British Gas bill, find out the *exact" tariff name. Check whether the most recent bill has an estimated, actual or customer reading. If customer, can you recall if it was the number you submitted. Regardless, check that the number is "close" to the number on the meter today.
It would help in providing advice if you mentioned something about the household. How many rooms, what type of heating system, is the heating on a timer and/or thermostats and whether you consider the house well insulated and how warm you like the house to be in winter.
Finally, and this may be an academic distinction for you, you have certainly mentioned a "cost" increase, but not a "price" increase. I cannot help further unless you post meter readings from the most recent and earlier bills.