The three major centres of South Africa are Johannesburg, Cape Town and Durban (in that order of size). Flights from Aberdeen to Johannesburg and Aberdeen to Cape Town have at least one stop, whilst flights from Aberdeen to Durban have at least 2 stops.
If your plans are to fly to Durban, first fly from Aberdeen to Johannesburg (or Aberdeen to Cape Town), and then catch a local flight (or bus or train) from Johannesburg to Durban (or Cape Town to Durban). The links below contain a full list of airlines operating flights on each route and links to their online flight reservation systems.
There are more airlines operating flights from London to South Africa, than from Aberdeen. You may therefore wish to see a list of airlines operating flights from London to South Africa (so that you can travel from Aberdeen to London, and from London to South Africa).