This site connects you directly to corporate employees and is the fastest way you can get connected to Corporate and have them investigate your issue.
Auto payment is the default payment method for the service, though you can also sign up for paper billing, which costs an extra $5 per month.
The information about billing should have been given to you by an agent when you set up your account. The welcome email also tells you that you will be charged automatically each month.
You may also want to read the subscriber agreement, section 5, to see how the dispute resolution process works.