I'm not exactly sure what you mean by "recycled". Perhaps you mean the GDG was defined with the "EMPTY" attribute which means that all the generation data sets are to be uncataloged when the maximum is exceeded.
If the data is gone then the only way to recover it is to restore it from a backup. However, I don't have enough information about your environment to tell you if the data was indeed backed up, by what method and how to restore it if it was. Your best bet is to contact local support people that hopefully can help you get your data restored.
This was first published in March 2006