I ignored her for a day and she blew up my phone with texts. I replied "hey how are you" and she says "why havent you answered", "what did i do?"

How do I reply? Do I just say I was busy, cuz I feel like anything I'll say she will call bs and keep annoying me about what she did wrong (was obvious to me) and i obvs dont want to explain. She is rlly clingy/needy btw.