The provisions of this Chapter shall not operate to the prejudice of any right to which a person employed in a mine may be entitled under any other law or under the terms of any award, agreement or contract of service:

Provided that if such award, agreement or contract of service, provides for a longer annual leave with wages than that provided in this Chapter, the quantum of leave, which the person employed shall be entitled to, shall be in accordance with such award, agreement or contract of service, but leave shall be regulated in accordance with the provisions of sections 50 to 56 (both inclusive) with respect to matters not provided for in such award, agreement or contract of service.