Based on these numbers, I calculate your loan amount in the neighborhood of $21,000 - at 11.55% APR for 72 months, the interest charge (if you pay the loan to term) is in the neighborhood of $8,200.
There are too many variables missing to comment yet.
How much was financed?
For how long?
APR - 11.55%
Was there a trade in?
If so, was a balance owed against it, and how much?
What was the price of the vehicle you purchased?
Downpayment amount?
Did you purchase additional warranties or...