I'm not sure exactly what your problem could be as you didn't give much of a description of what you have done so far to correct the problem. Have you collimated the mirrors? Without proper collimation, you will never get a sharp image at the eyepiece. If you have problems doing this, or need the proper collimation eyepieces, let me know. We can get together and I could do the initial collimation for you, it only takes about 5-10 minutes to do.
Here is a link to the manual for the scope you have: