A teacher called me mentally unstable, what should I do?

I was mumbling a song (in a low voice) in the class while taking out my books from my bag and I didn’t realise that the teacher was standing right next to me, as soon as I saw anger on her face and I apologised to her immediately, and she starts asking me that if I’m mentally challenged or not and started calling me abnormal and told me not to sit around my friends because she thinks I’m abnormal and would spoil my (mentally fine) friends and shouted me to go and sit at the far corner of my class away from everyone. I decided to complain about this matter to my class teacher, she took me to the head mistress to let her know about this situation, as I was explaining her what exactly happened then she told me that she will talk to the teacher about it. But it’s been 2 days and I really don’t see any change in that teacher’s behaviour. Is there anything else I can do so that some sort of action is taken against this teacher?

she has stopped but still makes reference to that incident over and over again to the whole class