Just keep checking. As with any plans, changes happen and people have to cancel and move things around.
Before you are too hard on yourself, it is confusing that they have the times running up to a point with the 24 hour clock and then they change it to 12 hour clock. It means you have to double check each time so carefully. If they were consistent and just picked one and stuck with it, these problems could be avoided. I am 100% certain you are not the only person this has happened to. If you don't get anything before, try reschedule it on the day if you can