Delirious

Last year on 10/1/05 I took out a medical loan of approximately 4k with Capital One. It was 12 months no-interest. I paid the minimum amount regularly each month on time. I planned on paying the full amount before it was due otherwise the 19% interest would be owed from the full year. However things in my life got kind of hectic and although I didn't forget about the loan, I expected to receive a notification that it was due. The due date was 10/1/06 which came and went. I received a normal statement which listed the balance as of 10/6 and nothing new. I decided to call a few days ago and they told me that in addition to the 2800 I owe, I was also now responsible for the additional interest which was about an extra $800. I spoke to a supervisor and explained the situation. He said there was nothing he could do.

Does anyone know if there is anything that I can do at this point to avoid paying the interest, or am I screwed?