As much as I dislike 123-reg, they weren't the only ones who did the 'auto-registration' thing. I don't feel like dropping my registrar in it but they did the same (only it was at the end of the .uk reservation period - I gained 2 domain names, both of which ought to belong to clients of mine). I haven't ever checked if they set them to auto-renew in fairness, my account settings are to NEVER auto-renew so I suspect they followed that.