I booked a few domains through 123-reg back in April, that were due to drop in May and June.
It was all auto, though very slow to get a confirmation of the booking (maybe not so auto then).
I then had to cancel 3 of the domains about a week later (client change of mind). Couldn't do it through the control panel, cancel button not working, so contacted support.
They got back and said they were cancelled. Week later, still sat there ready to be caught. Contacted again, told it was all cancelled.
Drop date comes, and the buggers register one of the unwanted domains I cancelled, in my name. I'm still getting emails now 'Your caught domain is awaiting payment'.
Needless to say, they didn't catch the domains we wanted.