I've been working at my current company for around a year and a half now and since I started I have been given the nickname "Droof" that I don't particularly like. I've done my best the past couple of months to try and phase it out and get people to use my actual name but my co-workers think I am joking when I make that request. It's got to the point where there are people within the company that only know me by my nickname and get confused hearing my actual name in conversation. Personally, I find it quite unprofessional when my nickname is used to third party clients and new member's of the business.
Is there any way of trying to phase a nickname out when it is used by everyone I know within the company i'm at?