student loan repayment

I am new here. I hope I'm posting in the proper area. My problem is that I have a previous student loan through Sallie Mae and for over one year now I have been enrolled in a new school full time. The original school loan is supposed to be in deferrment status until six months until after I graduate. Recently Sallie Mae sent me a bill and have been calling and harassing me about 10 times a day saying I'm behind on my bills and I owe all kinds of money. I have told them I'm in school and had my school send notarized transcripts showing I am attending school, but they won't leave me alone. I barely have enough money to get by every month and now they expect me to pay. Any help would be appreciated.