Can a manager change your schedule at the last minute?

I got a flat tire yesterday as I was heading home from work. I had a really bad spare and my car is pretty uch undriveable. I had the day off today so it was the perfect time to fix my car. Well, I got a text message this morning from my manager asking me to come in at 11. I say I can't and that I am sorry. Well later on at 10:30 I check my e-mail and my manager modified my schedule to come in at 11. I figured since I already spoke to her she understood my situation that I can't come in. She calls me at 11:10 asking me why I am not at work. I tell her cause I was scheduled to be off. She starts going off on me telling me I HAVE to come in. I was like well I was scheduled off and I have no car. You can't schedule me to work at the last minute without telling me. I spoke to the GM and he said the same thing. He told me it must of been modified last night cause she printed out the schdule this morning so its my responsibility. I check the date and time it was modified and it was today at 7am! Am I wrong fro standing up to myself? They gave me no notice at all. Not even a phone call! He apologized cause he finally understoof where I was coming from but I'm still kinda upset. I do my job with no complaints and I felt I was treated unfairly.