Job sent me letter saying we’re shut down for the week and now being told last minute it’s canceled.

I got sent a letter in the mail weeks ago saying that the line that I work on in the warehouse is being shutdown for repairs. As soon as it starts I’m being told that it was canceled despite no one telling me anything about it being canceled and they want me to come in. Surely this can’t be allowed right? If anyone has any advice on how to handle this would be much appreciated.