Atlus, with humble apologies and thanks for your patience proudly re-released the downloadable content for Disgaea 2 on the Playstation Network. A quick note from them about it:

First of all, we’re happy to let you know that the fixed Disgaea 2 DLC is back on PSN! We really appreciate that all of you have been patient with us while we fixed the problems with the DLC.

If you already purchased the Disgaea 2 DLC when it came out you should be able to simply re-download the DLC. Please do let us know if you have any problems with re-downloading.

As for the Saphire and Plenair characters, we are working on setting up the refund system for those who purchased Plenair and Saphire character DLC. We appreciate your patience.