Gratuity based on years worked, current salary

I worked in a private school as a teacher for more than four years on a visa that did not belong to the school where I am working. Only two years ago, the visa was adjusted by the school. When I became legal in the school after the adjustment, a dispute arose between me and the school management which ended in my termination. When I claimed my labour dues, the school principal said that she would calculate my service period on a two-year basis only, on the basis that my employment the other two years was against the Labour Law. My question is; in case I failed to reach an amicable solution with my school management, shall I request the Ministry of Labour to refer the case to the concerned court?

1. What is the position of the concerned court with respect to end-of-service gratuity for the previous period of the visa when I was not on the school visa?

2. The salary I am getting now is more than the salary which is mentioned in the Labour Contract, so I want to know whether the end of service was calculated according to the current salary or the salary mentioned in the Labour Contract? Please advise.

The labour court will calculate your full rights for end-of-service gratuity from the beginning on your actual employment with such school, not from the adjustment date of the visa. Furthermore, with regards to the end-of-service calculation, under the Labour Law it is calculated on the basis of the current salary that the employee is receiving.