You can enable credit promotions in the "Credit promotion" category found in the features for your platform. This allows you to offer free additional credits with every credit purchase.
You can use this to encourage customers to buy credits. An example of when you could run a promotion is Black Friday week.
When you enable promotions you can configure when the promotion starts, so you can schedule promotions in the future.
The start and end dates and times are in your local time zone. The promotion is automatically stopped when the final date and time have been reached.
Here you can also specify the percentage of extra credits based on the customer's purchase. When you offer 20% extra credits and the customer buys 10 credits, the customer gets 12 credits credited to their account.
The full amount (including the free credits) is taken from the customer's account whenever an order is refunded.