How to Handle User Email Confirmation After User Becomes a Paying Customer And Doesn’t Confirm Email

I'm rebuilding my "confirm email" system when a user signs up or changes their email. Websites like Facebook require an email be confirmed each time it is changed, so I have implemented the same. However, if a user does not confirm their email after becoming a paying customer, there is seemingly no way to contact them should something happen with their account...

Scenario:

  1. User signs up for the website
  2. Website sends email confirmation
  3. User confirms email
  4. User signs up for paid subscription on website
  5. User changes email
  6. Website sends email confirmation
  7. User does NOT confirm email
  8. Website is unable to communicate with user...

I realize that it's the user's onus to confirm their email, but I could easily see this slipping through the cracks... and by them not confirming their email, it could result in a cancelled subscription or them missing password reset emails.

Is there a general way to go about solving for this scenario?