We regret that this misunderstanding has occurred

We regret that we are not in a position

We regret that we are unable to grant your request

We regret the necessity of calling your attention

We regret to be compelled for this reason to withdraw the privilege

We regret to learn that you are disappointed

We remain, dear sir, yours faithfully

We remain, gentlemen, with thanks

We shall await your early commands with interest

We shall await your reply with interest