How do I get a Refund

Re: How do I get a Refund: I already deleted an app but the payment is still going on,

it took the money in my gcash, the app was downloaded by my niece accidentally

As payment is still going on you may need to cancel an ongoing subscription:

If you want to cancel a subscription from Apple - Apple Support

How to: Request a refund for apps or content that you bought from Apple - Apple Support

If you wish: You can make sure your approval is necessary for any downloads:

Require a password for App Store and iTunes purchases - Apple Support

or

Manage App Store purchases, subscriptions, settings, and restrictions on iPhone - Apple Support