Google has a new payment policy that applies to all subscriptions and apps (not just Lingokids). With this new policy, Google will make a pre-authorization request for the charge, where the charge is initiated, but not processed completely. If you cancel your subscription, the charge stops, and your money is released back to your account.
You can find more information about this on Google Play's help pages. As you can see, if the status of your subscription on Google Play is "Canceled," the order was never charged and you will not see a credit on your form of payment.
You can also confirm the status of your subscription in your Google Payments account.