The Minister may, in any particular case, subject to such conditions as he may deem fit to impose-

(a) exempt any person or class of persons from the payment of the whole or any part of the sales tax which otherwise would have been payable by such person or such class of persons;

(b) direct the refund to any person or class of persons of the whole or any part of the sales tax paid by such person or such class of persons; or

(c) direct the refund to any person or class of persons of the whole or any part of the penalty paid by such person or such class of persons.