So i have 2 roles at a company i have been working for for nearly 2 years. One of the roles is as a performer and i get paid per show i do with no guarantee of how many i will get a week (average is around 9) i was also offered a role as a designate duty manager which i did alongside when not performing usually between 1 and 2 8 hour shifts a week. I have always accepted that as a freelancer there is no guarantee of any hours. I have a contract for the performance role which is a rolling 6 month contract but never had anything for the duty manager role. I do have emails and invoices for everything. A few months ago the company employed a new managing director and general manager and yesterday i was told that unless i take a zero hour's contract i cant be a duty manager, a long story short i am currently going through buying a house and to go onto a zero hour contract will affect my mortgage so i had to decline. Therefore I have suddenly lost half my monthly earnings as they are saying as of now i cannot be a duty manager. Is there anything i can dispute with them? They are saying i should never have been allowed to do the role in the first place but I feel that its not my fault they gave me the role which i have done for nearly 2 years. Any advice would be greatly appreciated.