we have not even sat down to discuss the case together ans he is ignoring valuable leads that could prove my innocence
It sounds like you have a court appointed attorney or you are represented by a public defender. You can ask the judge for a new attorney. You would have to convince the judge that your attorney is not properly representing you. This may be difficult, but you have a lot riding on the outcome of your case.
The other option is to retain a private attorney that has will devote the time necessary to your case.
Note: For informational purposes only. Seek an in person consultation with an attorney to be informed about all of your rights.