If you already have already purchased an upgraded plan on SweepWidget, then you have an existing billing account with SweepWidget.
You can only change your customer billing information if you have previously created an upgrade plan.
First, navigate to Account Settings > Update Payment Method.
Next, you can click on either the Account Information, Payment Methods, or Billing & Shipping Addresses links. These will allow you to update your billing email address, payment methods, and address information.