Am I owed end-of-service benefits if I'm not on the employer's visa?

I worked in a private school for more than two years on a visa does not belong to the school where I am working. Only three months ago, the visa was issued by the school. Due to some problem with my school management I have submitted my resignation and the school management has accepted my resignation and ask me not to work for a notice period they are going to pay for that but my problem is that when I claimed my labour dues, the management said that I’m not entitled for end of service benefit on the basis that my employment within the two years was against the Labour Law. My question is; in case I failed to reach an amicable solution with my school, shall I request the Ministry of Labour to refer the case to the concerned court?

I would like to clarify to the questioner that the concerned court will calculate the questioner’s full rights for end-of-service gratuity from the beginning of her actual employment with school, not from the issued date of the visa. Furthermore, with regards to the end of service calculation, as per the Labour Law it is calculated on the basis of the current salary that the employee is receiving.