What is the best Approach

[94B10]

I have a student loan that is in the adverse section of my report because they are reporting a 30 day late in November of 2003. I was also on deferment for 3 years. I called them yesterday to ask about when my deferment dates were. The guy told me that it started February 2003 to February 2006. So then how could I be late if it was defered. How should I approach this, a goodwill letter or point out their error and ask them to correct it.

Thank you