In most cases, HR would stand on the side of the management (man

For the bosses like your, they can deny what they said / promised. The better way in the future is to use e-mail (written) communication. Even after the verbal communication and getting the verbal promise for something from the boss, you can always later send an e-mail to express the thanks and confirm the promise from the boss at the same time. It is hard for someone to deny something written in black and white. If you are in medical / food industry, there is a saying from FDA: not documenting something (written or eletronic signature) = not doing that something.