Redeeming miles for reward flights with a child ticket

Hi All,

I'm considering trying for 3x UC seats to MIA/MCO and the return of 3 X PE seats back to LON.

I did a dummy booking online and see that you have to phone if it involves a child. How do I go about this? Wait until 3 (adult) seats are available online (if ever) then phone? Is their phone line open 24/7? I don't want them to be available then snatched?

I've successfully booked UC reward seats online before, but this throws a curveball.

I would pick up the phone at once before they are gone

Chriski, sorry, I don't have them yet, just perspective for booking in next month or so. Don't understand why you can't book them online!