Debt Collection Question

[jws43yale]

In May of 2006 I rented a U-Haul can to move out of my dorms. I rented it for one day, turned it back in and was told all my payment was good.

Over a year later in late May 2007, I recieve a letter from U-Haul in the mail that I owe $40.00 for a parking ticket that I did not even know I recieved that day. I put the bill in a pile to call them about and two days later I receive a call from a debt collector telling me I now owe $70.00 which includes a $30.00 administrative fee.

I was leaving the country for a month two days later, so I did not worry about it, but I recieved a letter stating my debt owed during that month. It basically details the debt and says it is due within 30 days.

I am wondering if I have to pay any of this. I would rather not but don't want it to affect my credit. I was not informed of my debt from U-Haul until a year after the rental, and then was not given any time to pay before having my debt sent to collection.