Undervalued Staff - VFX Production Assistant MPC Employee Review

Working +70 hours per week under 19K per year, hourly rate of 5-6 pounds (illegally under minimum wage), got "promoted" to coordinator and neither my title is being acknowledged and officially changed, nor my salary reflects or will reflect the promotion, just a few people got the annual pay rise and I was told by my boss no one did, and that no one will until at least next year.