15. A pension, gratuity or other allowance granted under this Act shall not be assignable or transferable, except for the purpose of satisfying —
a debt due to the Government; or
an order of any court for the payment of periodical sums of money towards the maintenance of the wife or former wife or minor child, whether legitimate or not, of the officer to whom the pension, gratuity or other allowance has been granted,
and shall not be liable to be attached, sequestered or levied upon for or in respect of any debt or claim except a debt due to the Government.