What country are you in? We did get an email from Apple that they were going to be working on their system from Dec 22nd – Dec 29th. I wasn't under the impression that this was going to affect in app purchases for customers though. Here's the text of the email Apple sent out:
As a reminder, from Monday, December 22, through Monday, December 29, 2014, iTunes Connect, Application Loader, and iTunes Connect for iOS won’t be available.
During this time, you won’t be able to submit new apps, app updates, or In-App Purchases. You also won’t be able to access iTunes Connect or make changes to TestFlight Beta Testing. You can schedule an app release or price changes to take place between December 22 and December 29. Just make sure that your changes are scheduled, submitted, and approved by December 18, to ensure your app remains available during this busy period.