We'll be carrying out some regular maintenance on our payment systems on the 25th of November and due to this you may be unable to pay for Skype Credit or set up Auto-Recharge for short periods of time.
The maintenance started at 08:15 GMT and will be finished within couple of hours.
Once the systems are back up and running we will update this post.

UPDATE:
The maintenance was finished at 09:00 GMT and all systems are working normally again.