If a card payment fails, you'll get an email asking you to update your payment method (Dashboard > Settings has a direct link to the billing portal). A second failure sends a second warning saying Suzy will pause in 7 days if it isn't fixed.
After 3 consecutive failures, Suzy is paused for that property until the card issue is resolved. Updating your payment method in the billing portal reactivates things automatically - no need to contact support unless something looks wrong.