If you've ever run into a situation where a credit card/ACH transaction occurs in ASAP was done incorrectly, you may still be able to cancel this payment. Please first, review this support article explaining how Credit Card Transactions are processed in our system as well as how they are sent off to your payment gateway:
Credit Card Transaction Lifespan
The key thing to note is that an action taken outside of ASAP such as cancelling/voiding a payment does not automatically update this in ASAP. You would need to contact our support team in order to have this fixed within our system.
If you do need to cancel/void a payment made in accident, one of the first things you would need to do is to review with your payment gateway the time window in which payments are settled. Each payment gateway has their own window of time before they process a payment, with some that are done automatically up until 2 days from when the payment was made. If your payment gateway allots you time to cancel unsettled payments, then you can further proceed with this process. If not, you will need to process a refund directly in ASAP as the payment has settled automatically and there is nothing you can do within your payment gateway.
Since the payment occurred within this time window, you should still have a chance to cancel/void the payment as it most likely has not settled. You or someone that has access to your payment gateway account would need to login and void it directly in there. Once done, we would just need proof or receipt from you showing that the transaction was voided. Screenshots, image files, PDFs, etc. may be accepted as proof that the payment had been cancelled within the payment gateway. After that, just forward into our support team showing the payment had been cancelled. From there, we'll update in ASAP to show the payment as 'FAILED' since it's now a voided payment.
Here are some other helpful articles that may aid in assisting you with why you may need to perform these actions:
I have processed too much on a payment and refunded my student, how come they don't show a balance due?