is it costing me extra if my ac isn’t reading the temp right?

i’m 95% sure my ac reads the temperature wrong. it feels cooler than what it reads as, some people told me i would get charged more because of this but i don’t understand why it would? especially if it’s reading higher than what it is. i keep my house at around 80 all day and i live in arizona. sometimes i need a blanket when it’s at 80 or above so there’s no way its right. should i get it fixed or does it not matter at all?