Obviously I don't know where you were travelling from and to or what kind of ticket you had, but in principle should not AWC have been obligated to sort this out for you, or does the fact that you had advance notice mean it was all down to you?
I'm just interested for if/when this ever happens to me! Thanks.
I believe that these days the industry now works on the principle that the timetable is whatever they decide it should be by 22:00 on the day before travel (the "published timetable of the day"). Any other timetable (printed one, journey planners consulted before that point) are just indications of what they aim to provide.
So in their view they aren't cancelling the last train of the day, they're just providing a timetable on that day where the last train runs earlier than when the ticket was booked, and therefore they have no obligation to provide an alternative.
Just to make this even less helpful, there doesn't seem to be any simple way to find out whether changes were made before or after the magic 22:00 deadline.
This may or may not actually be legal.