US Department of Education has not applied my December 2011 payment to my account. They have cashed my check (electronically) on December 19, 2011 but will not apply it to my account. It now shows I am delinquent which is incorrect. I have made all of my payments on time. I have spoken with several customer service representatives and two supervisors, all apologizing and stating they will correct this error. Nothing has been done and I feel I am getting no where with these people! I work hard and strive to have great credit and I don't want this held against me.