Any person who contravenes or fails to comply with this provision shall be guilty of an offence and liable on conviction to a fine not exceeding R1 000 or to imprisonment for a period not exceeding six months, and, in the case of a continued offence, with an additional fine of R5 or additional imprisonment of one day for each day on which the offence continues: Provided that the period of such additional imprisonment shall in no case exceed 90 days.