It may happen that if you have paid for the subscription plan in InvoiceOcean and you are logged in to your account, when browsing the price list, you accidentally choose a different plan than the one you have paid for. It is also possible to change it from your account in Settings> Account settings> Change account type.
Then the program will take you to the Payment page.
You can also go to Settings> Account Settings and follow the same steps as above> click HERE.