Is it permissible to demand salaries and other contractual entitlements after arbitrary dismissal, knowing that labor law rules in my favor, and does this conform to the Islamic legal opinion?

Jobs fall under the category of hiring individuals, which is a binding contract that can only be dissolved with the consent of both parties or due to an unforeseen necessity. Accordingly, if your contract was terminated without a valid excuse, you are entitled to the salary until the end of the contract period, because a private employee is entitled to compensation by making himself available, whether he worked or not. If the labor office rules that the termination was arbitrary, then there is no blame upon you for taking the remaining salaries.