My employer has told me that they are changing my role from managing a team of 10, the complete workforce, to not managing anyone. A new Manager will be brought in. This is in affect a demotion. As part of the change they are taking away my 1% commission on sales. I have not had an appraisal interview or any form of disciplinary hearing. I have worked for the company for three years but do not have a written contract of employment. Is this legal and can I do anything about it?