Step 1: Delete product
Select the customer whose product you want to convert into a credit pass. To select the customer, you can either use the Search bar at the top right or the Customers option on the menu.
Click on the row containing the wrong product to display the different options. Next, click the "Delete" button.
A new pop-up window will open in which you have to select the option "Delete completely" to delete the product completely. The customer will automatically be issued with a credit pass equal to the value of the product.
Step 2: Add the right product
Next, add the correct product.
Stay on the customer's page and click on the button "+ New product".
A new pop-up window will open in which you can select a payment method that is not immediately marked as paid. You can use e.g. "Bank transfer" or "Pay later".
Then click on "Confirm" to save the changes.
Step 3: Use credit pass as payment
The new product can now be paid for with the credit from the old product.
Click on the button "New payment" in the customer profile and select the negative as well as the positive amount. If both amounts are the same (e.g. 100,00€; -100,00€) the customer does not have to pay anything more. The product is considered paid.
If the new product is more expensive than the old one, the customer has to pay something in addition. So, it is best to do this only if the customer has actually paid the correct amount or the exact missing amount (here 80,00€) was settled afterwards.
If the new product is cheaper, then the remaining amount must be returned to the customer immediately or in advance according to the chosen payment method (e.g. in cash).