Does the Higher Educatiol Act of 1965 give lenders like SallieMae the right to make harassing/repetitive phone calls?

I am fighting on going battle with SallieMae. They make harrassing phone calls after payments and or special arrangements have been made. I recently reported them to the better business bureau and received a letter basically stating that they can continue this (if a loan is in deliquent)harassing behavior under the Higher Education Act of 1965. However I've called many time to make arrangements due to recession times and I am told repeatly that there is nothing they can do so the calls will continue. How is this legal?