Stop user's time

hello. I have freeradius2 on my centOS and it works fine! But now i want to add new feature. I want to disable user and stop his time. I am disabling user by adding auth-type := reject but he's time is not stopping. How can i stop user's time? For example user john have 25 days and i disabled this user for 2 days. This 25 days must be continue after 2 days. I hope there is a solution. Sorry for my bad English :(