How set Recipient status of exception

I am trying to set the recipient status as 'accepted / decline' of recurring
appointment using extended MAPI PR_RECIPIENT_TRACKSTATUS.

It is working fine for Master event. But for Exceptions to series showing
some weird behaviour.

For excepion, status is set as Accepted but if outlook is closed and opend
again this status is goes back to old status.

For example: If status of particular recipient was 'Accepted' previous and
it changed to 'Decline' then when outlook is re opened it goes back to
Accepted.

Thanks in advance.