What is the name of your state? new york

hello all!!! my case is about a 2-year college trying to charge me money for withdrawal...

I graduate from high school last year and didnt think about going to college... so i decide to try a 2 year college first in August. The full tuition per semester is $3600 and they told me that i can pay the first month first to see how i like the school so i pay $900 for the month. After that month i figure it was better for me to go to a 4 year college so i decide to withdraw, i spoke to the college office and they come with the sorprise that i have to pay the full semester tuition for me to withdraw...

Now my question is if this legal cuz i told them i just wanted to try out and they said it was ok and they are saying tthat i had to withdraw within the first 2 weeks and they show me a student manual that they first gave me about the refund policys but the onlu problem is that im not asking for refund.... and i pay them with cash...
they said they are going to charge for the next semester too if i don't withdraw. The funny thing is that i asked them if that means that i can go to class without paying them and they said they never said that....

I don't have the money to pay them, my mom is not workiing and i gotta take care of my 2 little sisters, im working on 2 job to cover all the expenses and i don't want to just hang them the money.

And they call my house almost every day... my family is really annoy with all this, i don't know what to do , please help!!!!