SqlCounter reload after initial authentication

I'm using Freeradius + Chillispot+MySql for hotspot. Sqlcounter noresetcounter works fine for prepaid access time, however the counter is loaded only once when the user first authenticate. This means that even if Max-All-Session changes after initial logon (as it happens when the user adds more credit) the user is session is still terminated at the end of the initial count down. How can I force Freeradius sqlcounter to re-load and begin counting down when Max-All-Session is updated after initial authentication? If this is not possible any workaround or hacks to accomplish this behaviour will be greatly appreciated. Thanks.