Does anyone know why my movies are automatically being charge at the 30-day rental rate when I rent themf or just one day?
Sounds like it might be something going on with the billing. While I've not sat down with FiOS TV a lot since I do not have FiOS available to me, when you are ordering movies are you sure you aren't selecting the monthly rental option? Are movies available that you order for the entire month?
I'd check with Billing if you can answer no to the above questions. They should be able to credit the account for the non-use and also see if they can solve the overbilling issue.