Manager mad that I won’t come in on my day off. Should I bring this up to her or contact HR?

Since another employee has been requesting additional shifts, I've noticed that my manager is cutting my hours. However, my manager texted me and asked if I can fill in for that employee because they are not available anymore. I replied that I made plans on the days she scheduled me off. She seemed upset by my reply and has given me the more demanding/difficult shifts. Should I bring this up to her or contact HR?

Updates
+1 y
I'm definitely planning to quit! The recent work schedule that came out from my manager shows me working one 8-hour day out of the six days available. This confirms my decision to follow people's advice of quitting to find better and I do genuinely believe that there is better out there. Appreciate everyone's input and thank you!
Manager mad that I won’t come in on my day off. Should I bring this up to her or contact HR?
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