Is it mandatory I pass my first year BTEC exam to pass the entire course

I’m in my second year at college and take applied human biology as a btec. I passed all my first year course work with pass, merit and distinctions, but failed my final first year exam for that course. I was told by my first year teacher that it isn’t mandatory to pass that exam to complete the course but my second year teacher said it is mandatory and that if I don’t get at least a pass on my first year I’ll fail the entire course. She put me in for a resit which she told me would be £10 and turned out to be £50, something I cannot pay for as my family isn’t financially stable (something which the college is aware of). I looked on my college portal and found out I can’t even pay for it anymore as it doesn’t even come up as an option and I’m not put down for a retake. My predicted grade for that subject is a merit which can rise and fall depending on coursework results and final exams. Surely if they let me into my second year despite failing and my overall grade right now is a merit I wouldn’t have to retake the first year exam. And surely they wouldnt have let me know I was retaking it at the start of Apri , 2 months before the retake date. My college aren’t helpful in the slightest right now