There are a few reasons that your application may be experiencing higher than expected outgoing bandwidth. For more info on your requests, I highly recommend
downloading your logs using the appcfg tool and analyzing them, and bear in mind that all outgoing traffic, including URLFetch requests, data sent in email message, data sent over the Channel API, and data responses all add to the total.
You can open a ticket with our Cloud Platform Billing Team by performing the following steps:
2-Click on 'Contact Us' in the upper-right corner
3-Select 'Billing, invoices or charges'
4-Select your Support Package
5-Click on the blue envelope
6-Fill out the form regarding your issue, the more information you can provide, the better equipped we are to help
7-Press Submit
8-You have now opened a ticket! A Billing support team member will contact you shortly to resolve your issue with you.
Cheers!