Credits he an expiry date attached. You need to use your credits in between one year.
Please contact Adobe customer service for more insight. On this user to user forum (with some Adobe participation) account problems can't be solved. Adobe customer care can be contacted here: https://helpx.adobe.com/contact.html - click the small callout at the lower right of the screen and type "agent".
ABAMBO | Hard- and Software Engineer | Photographer