Is the worker entitled to claim compensation for his years of service after his dismissal, given that he was receiving a monthly wage, and what is the Islamic legal ruling on this claim?

End-of-service gratuity is either a part of the worker's wage—if it is stipulated in the employment contract or established by custom—and is considered a deferred part of the wage paid at the end of service. Or it is a gift from the employer—if it is not stipulated by the contract or custom—and a gift is not binding until it is seized (received).