Other than going to the send a request through the help desk and asking the devs, you should be able to go to your account page and look at past invoices. It should show the date processed which gives you a rough idea of when you are charged. As for the benefitts. If you cancel your subscription, they last till the end of your current subscription duration. Supposed that you subbed for a year and canceled 3 months in, it continues till the end of your sub year. If you subbed for a month and canceled during that month, it ends at the end of that sub month.