how can i cancel my pending purchase

I can't see any Pending purchase on your posted images.

If your payment method is declined in the App Store or iTunes Store

You can't make purchases or update apps until you change or update your payment method.

If you have an unpaid balance in the App Store or iTunes Store, you might see one of these messages:

• "There is a billing problem with a previous purchase. Please edit your billing info to correct the problem."
• "There is a billing problem with a previous purchase. Click Purchase History to view and correct the problem. If you cancel you will not be able to buy until this billing issue has been resolved."

To resolve this, add a new payment method or update the billing information for your current payment method. Your unpaid balance will be charged. Then you can make other purchases and update your apps, including free apps.