One of the most common reasons for that is when there is an invoice overdue. When a payment — for whatever reason — can’t be processed, the system will temporarily downgrade the account.
To solve this problem, you need to add another card on Subscription Settings, switch the payment method, or contact firstname.lastname@example.org if you need a manual attempt to your current payment method.
Once the overdue invoice is paid, the Premium/Business account will automatically reactivate, and all the Premium/Business features will be available.
If you are sure your payments are up to date and the system still treats you as a free user, you may want to check your limits. If you still think there is anything wrong, please contact us at email@example.com.