IS there anyway possible that i can repair my credit?

I had applied to an number of banks for student loans, and lines of credit so i could gather the needed finances to purchase a laptop, travel to Louisiana, and cover any other incidental costs, I kept getting denied, even though most of the loans were specifically designed for college students with no credit.

I check my credit and find that I have a collection agency for Verizon claiming that I owe $357 in august 2006

I wasn't even 18 then, how could I have an account with verizon, currently its under investigation because I disputed it, it wasnt me who made that transaction.

Like I said, is there anyway to repair my damaged fico score?