I added a gift card 20 and 5 doller 2 cards and i parchase 11.99 and i got after purchasing 3.56

See the following Apple articles:

View your purchase history for the App Store, iTunes Store, and other Apple media services

View your purchase history for the App Store, iTunes Store, and other Apple media services - Apple Support

How apps, content, and subscriptions from Apple are billed

How apps, content, and subscriptions from Apple are billed - Apple Support

Request a refund for apps or content that you bought from Apple

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

-> If you have requested a refund, you must wait until Apple has approved. Then you will receive a message from Apple.

See the following Apple articles:

If you want to cancel a subscription from Apple

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

If the subscription that you want to cancel is not listed

If the subscription that you want to cancel is not listed - Apple Support

If you have add funds to your Apple ID balance, it would take about 1 to 3 business days.

Check again -> Check your Apple ID balance

Check your Apple ID balance – Apple Support (UK)

If necessary, contact iTunes Support for assistance. See the Apple Support articles below for contact information.   

iTunes Support – world wide   -

Apple Support schedule phone call     -

Billings and Subscriptions   -

Apple on Twitter