An online brokerage sold stock on my behalf due to a merger in 2020.  It required me to sign a form before receiving a proceeds check.  I did not sign the form or receive the check in 2020.  Yet the broker sent a 1099-B to the IRS, implying that I have received the proceeds.

Am I still liable to pay the income tax on the proceeds even though I never received  any proceeds?

Is the broker within the law by reporting the proceeds to the IRS without delivering it to me?