Do I have the right to file a case against my ex?

my x and i were not married but we have an 8 year old son his been paying school sense our son start school but now he said he want me to pay for school now because he needs to pay for there house bill for about 1million pisos.

Im so mad at him because just for that reason he will set aside his responsibility for our son that easy and i don’t think this is acceptable at this point. im very confuse i want to fight for my sons legal rights his a seaman and im wondering if i have a right to file a case against my x

hope you could help me.thank you!