(4)Where, in exercise of the powers conferred by clause (b) or sub-clause (i) or sub-clause (ii) of clause (c) of sub-section (2) of section 103, any existing permit is cancelled or the terms thereof are modified so as to prevent the holder of the permit from using any vehicle authorised to be used thereunder for the full period from which the permit, would otherwise have been effective, the compensation payable to the holder of the permit for each vehicle affected by such cancellation or modification shall be computed as follows:(a)for every complete month or part of a month Two hundredexceeding fifteen days of the unexpired period of the permit rupees;(b)for part of a month not exceeding fifteen One hundreddays of the unexpired period of the permit rupees:Provided that the amount of compensation shall, in no case, be less than four hundred rupees.