Sallie Mae Servicing charged excessive interest, even charged interest on loan portion paid Wilkes Barre Pennsylvania

About 3 years ago I enrolled in a MCSE course through the Junior College. the course cost about $7,000.00. the school inform the class to make all payments to the College. Before the course started I paid $3,000.00 of the student loan to the school. This was credited by school. Four months later I paid the school another $2,000.00. This left a balance of what I thought would be $2,000.00. However 2 months later I recieved a letter from Sallie Mae servicing showing me what the interest and balance due was, but only the first 3,000.00 was listed as paid. What was puzzling I was charged interest on the entire amount regardless that I paid 3,000 before the class even started and less than month after the loan agreement. Sallie Mae servicing stated that they never received the 2,000.00. eventually I check with the school they assured me that all money was sent, they gave me the name of the person at Sallie Mae who handles the payments for the College. after going back and forth for close to 2 months Sallie Mae finally admitted that the recieved the payment and it was posted under the wrong code but the will not abate the interest. Long story short the final bill sent was for close to $3,000.00, based on the full amount and the refuse to change it not only that it was rising fast. I began making on the remaining balance paying double the amount per month. I figured I knock it out and by the end of the and be done with it.
By the end of the year my bill due was over $2,000.00. No matter how often I paid it wasn't going down every time I spoke with someone at Sallie Mae they would tell me it is going down.
Eventually I said enough so I check with them on a payoff they told me which was over $2,500.00 had to be in so many days I sent a check registered mail it was recieved 2 days before due.
I'm thinking thats over, Nooo! I get a letter stating that I owe $17.00 which interest will be due soon. If this is not being ripped off I don't know what is.

Theodore
Bolingbrook, Illinois
U.S.A.