That's the reason why you have this exception:
[quote]EXCEPTION 3-- /APPLICABLE TO JOURNEYS ORIGINATING IN AFRICA EXCEPT SOUTH AFRICAAND ZIMBABWE/ TWO INTERCONTINENTAL ARRIVALS AND TWO INTERCONTINENTAL DEPARTURES ARE PERMITTED IN EUROPE. ONE OF THE INTERCONTINENTAL ARRIVALS/ DEPARTURES MUST BE A TRANSFER /WITHOUT STOPOVER/ IN LONDON OR MADRID ENROUTE BETWEEN AFRICA AND ASIA/AUSTRALIA/NORTH AMERICA/SOUTH AMERICA.[quote]
Enjoy.