I think the fact that you made an effort to reschedule with ABC shows them that you are interested.
If you simply said, "Sorry I can't because I already have plans" and left it at that, ABC might have thought you weren't interested.
At least that's how I would take it anyway.
Be sure to follow-up with ABC to see which night next week they'd like to have you over. If you follow-up, it would also show your interest in meeting with them.
