We have Allow requesters to reopen their own requests? set to YES because we want users to be able to re-open for a predetermined period of time, but not cases that are over a week or 2 old.

We also have When the requester replies through E-mail / Portal to the closed requests. Perform the following: set to Reopen the same request within 7  days from closed time. Else, create as a new request.

however, users can still go to the portal and re-open cases months or even a year old. How can we prevent users from re-opening a case after x number of days?