Well, I'll go out on a limb and advise the OP to call reservations again and calmly explain your situtation to the agent who answers. It is key that you not raise your voice or display any form of anger (and I'm not suggesting that you would) --- just keep it in the middle of the road and explain that this was an unauthorized cancellation from a source unknown to you.

[Any pax on earth would consider this sort of thing to be in the "worst case scenario" for travel plans. Book a reservation months ahead and then have it mysteriously cancel at the doorstep of holiday travel. Yuck.]

Anyway, back to the reservations agent. If that person seems befuddled, I'd strongly encourage you to politely ask to work with a res supervisor and really plead your case. These gals are still able to pull some pretty amazing rabbits out of their hats when pressed to do so. Not sayin' this will work, but it's well worth a shot.

More often than not, when I've had similar, outrageous, unthinkable things happen to my airline reservations or plans, a calmly presented case to the right person in reservations can quietly move mountains.

Good luck and keep us posted.