This is typical of the situation where you have actually opened multiple candidate spaces with different email addresses.

Your situation:

• You opened an account with one email address and for example made your payment on that account.
• You had opened another account with a different email address, and it is on this account that you are now logging in, only to find that your payment does not appear.

The explanation:

• The system is not capable of identifying that it is the same person behind two different candidate spaces. In this case, remember which account you made your payment on and continue your application on that account to consolidate everything into the same account.

Under no circumstances should you make a payment on one account and fill out your application on another account. You will indeed not be able to complete your application on any of your accounts by spreading the information from your application across multiple different candidate spaces.