cancellation and refund

If you cancelled within the 14-day grace period, you’ll receive an automatic refund in 10-15 business days. It may vary some depending on your bank & region.

This is a public forum, not Adobe support... other users can't help
To contact support see the CORRECT ANSWER at this link
https://community.adobe.com/questions-6/contacting-a-real-person-at-adobe-433913

A refund will take up to 14 days
To Cancel https://helpx.adobe.com/manage-account/using/cancel-subscription.html
-be sure to keep the verification email you will receive when you cancel
Log in and go here to check your account to determine your status https://account.adobe.com
You may only get a refund if you cancel and are charged during the first 14 days of starting a trial
After 14 days the trial becomes a subscription and there is no refund

ADDED - you need to take your credit card away from your son
 

refunds are automatic, if you qualify:

understanding cancellation 

fees, https://helpx.adobe.com/uk/manage-account/using/creative-cloud-subscription-terms.html#cancel