What can I do?

I am stuck in a job that I hate. When I went for the interview it sounded good but over the last few months I am doing work that is nothing like detailed on my job description. I have applied for so many jobs over the last few months and no-body is responding to me! I have also registered with some job agencies who are no help at all. I am at my wits end - can you suggest anything, I don't know what else to do. I am looking for administration work and I am qualified for this type of work. I never thought it would prove so difficult to find a job in this area.