Cash Deposit RSU Didn't Show up on 1099-B

You may need to adjust your cost basis.  If you sold your RSUs, then that sale of the RSUs should appear on a 1099-B, and it is not uncommon for cost basis to be zero on the 1099-B.   The broker probably does not know your cost basis, and therefore, will include zero as the cost basis and leave it up to the taxpayer to enter the correct cost basis.

Your cost basis for your RSUs is the value of the RSUs on the day they vested.  Box 14 on your W-2 may include the value of the RSUs on the day they vested.  If it does, the amount in Box 14 has already been included in Box 1, Wages, and the Box 14 amount would then be your cost basis for your RSUs.  If you need to determine the per share price for your RSUs, just divide the amount in Box 14, by the total number of RSUs you received (the total number of RSUs you received includes the RSUs you sold plus the RSUs your firm sold to pay the tax withholding). 

Regarding the question in your second paragraph, if you did not sell any of your RSUs, then there is nothing to report on your tax return.   You are correct that there is no option for you because as noted herein, the value of the RSUs on the day they vested has already been included on your W-2, therefore, there is nothing to report on your tax return.  When you sell your RSUs, then you have a reporting requirement because you need to report whether you had a gain or loss.   Your firm probably sold some of your RSUs to pay the required tax withholding; however, you do not need to report what the firm sold on your behalf.

Keep your records, such as your W-2, so that if you should sell your RSUs, you will know what to enter as your cost basis.  

@liguo1617