Section 89 of Kenya Railways Corporation Act CAP 397: Overcharge and undercharge

(1) Where the amount paid for the carriage of any passenger or goods by the Corporation, or for inland waterways ports charges, is found to be incorrect, then if such amount is—
(a) an overcharge, the passenger or the person who paid the charge shall be entitled to a refund of the amount of the overcharge;
(b) an undercharge, the Corporation shall be entitled to collect the amount of the undercharge from the passenger or the person who paid the charge:
Provided that such overcharge or undercharge shall not be refunded or collected, as the case may be, unless a notice in writing containing such particulars as may reasonably be necessary is given—
(i) by the person claiming such overcharge to the Managing
Director; or
(ii) by the Managing Director, to the person against whom the amount of such undercharge is claimed,
within six months after the commencement of the passenger’s journey or the acceptance of the goods by the Corporation, as the case may be, so, however, that where such undercharge is caused by any information or description subsequently found to be incorrect such period of six months shall commence from the discovery by the Corporation of the correct information or description.
(2) Where a ticket issued under the provisions of this Act has not been used, a refund of the amount paid for such ticket, shall be given if, within two months of the date of the expiry of the availability of such ticket, a notice in writing containing such particulars as may reasonably be necessary is given to the Managing Director by the person claiming such refund.
(3) Where the person claiming a refund under subsection (1) or subsection (2) proves, to the satisfaction of the Managing Director, that it was impracticable for him to notify the Managing Director of his claim within the times specified in those subsections and that such notification was made or given in reasonable time, nothing in those subsections shall prejudice the right of that person to obtain such refund.