Good luck with Norton, because if you read their forums, you will see that they have exactly the same issues with their software. Nothing is guaranteed to protect 100% and if you read any reputable anti-malware forum they will tell you that and to take extra precautions. So what McAfee may miss today, Norton et alia may miss tomorrow. It's an endless cycle unfortunately, but understandable when you realise that malware is constantly being rewritten so it's an endless game of catch-up..
As far as credit card renewal goes, that was pointed out to you when you first signed up for a subscription in the EULA, or Terms of Service, if you had read them, and at any time you could have turned it off on the account page. Customer Service (free of charge by phone or online chat & linked under Useful Links at the top of this page) is always willing to refund any unexpected charges within a reasonable period of when they were charged. You can hardly blame McAfee if you never noticed the charge for two years.
Support for anything is best done live by phone or online chat, never by email, the slowest method, for future reference. Sorry if you feel badly treated and again, good luck with Norton. I suggest you make sure that their account page auto-renewal is turned off.
For what its worth we Moderators have repeatedly asked that auto-renewal of subscriptions should be turned off by default but unfortunately the sales department doesn't agree.