In the user profile "Manage Alerts' for PayPlans
COM_EASYSOCIAL_PROFILE_NOTIFICATION_TITLE_PAYPLANS
COM_EASYSOCIAL_PROFILE_NOTIFICATION_SETTINGS_PAYPLANS_FRIEND_PURCHASE
COM_EASYSOCIAL_PROFILE_NOTIFICATION_SETTINGS_PAYPLeANS_FRIEND_PURCHASE_DESC
No constant is found when doing a search in the language override (Site + Administrator).
It would be nice if you could update these.