McAfee Free Trial offer states "You can cancel at any time before you are charged." However, under How do I cancel the McAfee free antivirus trial?, the FAQ page says. "Go to your My Account to cancel your free antivirus subscription or the the auto-renewal settings seven days before the trial period ends." There is no way to cancel the trail on the website before this 7 day window.
The only way to cancel the free trial before this period is to call customer service. I hope this contract inconsistency is fixed soon, so that customers can easily "cancel at any time".