I pay the simple bill of $49.99 a month with auto pay. And I already payed my last bill on January 14th, and the next bill is February 14th. Why on February 3rd do I get charged a random amount of $28.17?
Did you compare this bill with your last two bills? Do you read the notes included with your statement?
Even though you have autopay you should read the notes on your billing statement every month for information about this. Equipment, taxes and surcharges all went up.