Meetme call plan - call hanging up after incorrect number

When a user enters a incorect conference number in meet me, the number is rejected (corectly), meetme ends and my call hangs up

exten => 0845,13,MeetMe(${RoomNumber}|cirsM)
exten => 0845,14,goto(12)

I get this message in CLI:
Spawn extension (call-office, 0845, 13) exited non-zero on ‘IAX2/’

what I really want to do is divert the caller back into the meetme app again. What is the next line number / priority that is called?

Any thoughts?

Cheers - jon