drascons - It all depends on what you complain about. You may first contact the company directly and ask the book of complaints to express your discontent. The leadership will take action. Appeal to more competent authorities fraught with severe consequences for director and company. You can learn more information about it on https://ndandp.co.uk/insolvency-claims/misfeasance-claims/ . But think first, if really this person offended you so much that you are ready to break his life and spend your nerves and time on this.