Your account can hold a credit balance. Credit is applied automatically against your invoices before your card is charged.
Check your credit balance
Go to Billing, then open the Credits tab.
Where credit comes from
Credit can come from referral commissions, a refund, or a goodwill adjustment from the Wordify team. The Credits tab lists each credit and how it has been used.
How it is used
When an invoice is issued, any available credit is used first, and only the remaining balance is charged to your card.