Blizzard made some changes to the scheduled Paid Character Transfers:
Tseric: Due to the current hardware failures the Paid Character Transfer system is being affected. No further Character Transfers or the Account Administration page will be available until this issue has been corrected.
For more information and updates to the status of the hardware failure please be sure to keep an eye on the following thread:
Also due to the current issues, all realms that were slated for release as a part of the Paid Character Transfer have been moved to Thursday July, 13th instead. As a result the realms that were due for release on the 13th will now be slated for release on Friday, July 14th instead.