If you have not been counseled and are fully eligible for promotion in the primary zone you cannot be denied appearing before the promotion board. That said, be careful what you ask for. In other words, make sure you have your stuff together before you stir the pot.
You need to take this matter through your chain of command. I would recommend you see your squad leader and ask to see the 1SG and Commander on open door policy. The commander and 1SG will not deny you the ability to see them on open door.
Once you have their attention respectfully and professionally request their assistance in appearing before the promotion board. Provide them the reference that states you should be allowed to appear before the board. Ninety-nine percent of the time you will appear before the next board. Then the ball is in your court and you need to make sure your uniform is ready and that you are properly prepared. If you fail the board it is on you.
Should the Commander and 1SG refuse your request to appear before the board ask to see the CSM and BN CDR on open door policy. Trust me, if you are in the right someone in your chain of command between the 1SG and BN CDR will stand up and give you the opportunity to appear before the board.
Take the emotion out of the issue, approach it as a professional. While I understand that sometimes Soldiers believe the chain of command is against them. In reality when the chain of command realizes a Soldier has not been treated fairly they usually do the right thing. You could also prepare a professionally worded memorandum formally requesting you attend the board IAW with the guidance outlined in AR 600-8-19.
AR 600-8-19, para 1-26(a):
“First-line leaders will counsel Soldiers who are eligible for promotion to PV2 through SSG without a waiver (fully qualified) but not recommended in writing. Counseling will take place initially when the Soldier attains eligibility, and at least every 3 months thereafter, and include information as to why the Soldier was not recommended and what can be done to correct deficiencies or qualities that reflect a lack of promotion potential.”
AR 600-8-19, para 3-17(b):
“If the CDR determines that a promotion is to be denied, the unit CDR will take action to deny list integration prior to the 15th of the month the Soldier’s name is identified for list integration. Failure to deny integration by the 15th of the month the Soldier attains eligibility will result in the Soldier being integrated onto the promotion standing list. All Soldiers denied list integration will be counseled, in writing, in accordance with the provisions of paragraph 1-26.”