You can always "Reactivate" a cancelled subscription following the steps below. This is helpful if you have a client who cancelled but that comes back or if you want to apply a new subscription plan to this client.
The benefit of reactivating a subscription is you can choose a new plan and begin charging your client without having to re-enter their credit card information. You can also then put the site back online.
1. From the Site Details page, click on "View or Manage Recurring Subscription" in the Client Billing window.
2. Click on "Reactivate Client Billing"
3. Choose a Plan or Create a New Plan to complete the order