You Must Have Billing Access
Only users with billing permissions can change plans.
Changing your plan
You can Downgrade or Upgrade your GoDataFeed subscriptions at any time from the Billing > Subscriptions page by using the Change Plan button in the subscription details.
Changing your plan is effective immediately. For example, if you upgrade your plan to Ultimate, then you can access import filters right away. If you downgrade your plan to Plus, then You will no longer be able to access ASIN Match.
If you are in your 14-day trial period, then you can change your subscription and the activation date will stay the same. You will only be charged for the subscription level and usage amounts on the billing date after your trial.