PayPal – Negative Balance

Hello, I am a Canadian of 15 years and I have a negative balance of $ 147.01 due to PayPal.
It has been negative for a couple of months.
I have not contacted anyone in PayPal yet.
PayPal has sent this balance to a collection agency: NCO Financial. I was wondering, do I have to return this money? What would happen if I did not? I still do not have a job but if I have an INS, would this affect my credit when I am of legal age? Please help,

Thank you.
Jason