You can check the Palcomix Official Site (NSFW) to see if older bundles have been moved to their legacy archives or "Back Catalog" for active members or subscribers.
If you are looking for a specific comic that was part of this combo, searching for the (e.g., "Palcomix Gwen Tennyson 2012") often yields better results than searching for the entire seasonal bundle. palcomix 2012 summer comic combo download