Manager not giving NSA

Hi, so this has been going on for last 4 months. We have a total of 15 pending NSAs that my Manager isn't submitting. I have dropped him emails every month and he always said that he would do that day only (which didn't happen). Last week, he said that I won't be getting the NSA as the previous project got ended and billing can't be done from the current new project. What can I do now? I have emails for the whole conversation. Thanks in advance