What should I do now?

I’ve been doing A levels for 3 weeks shared across sixth form and college, I’m federating doing doing 1 subject in college and the others in sixth form. This has been going well for 3 weeks but now i’ve been told by the head of sixth form that i should be doing music (my college subject) at sixth form because it’s available there and they’re “paying for me to go to college”. They say I have no choice but to drop college and do it all in sixth form but i’m not going to do that.