Approved commissions appear in your balance history as "Provision Partnerprogramm" (Subscription & Costs → Balance). In the Promotion → Refer a Customer → Payout tab, you'll see three totals: already booked, awaiting booking (review or waiting period), and currently payable. Below that is the list of your latest commissions with their status.
If a commission is canceled afterwards (for example, if the payment is charged back), it will be deducted from your balance again.