The Alliance of Arabic Sultanates, the only strong and independent Muslim power after the defeat of the Ottoman Empire in the Franco-Turkish war, agreed to help Congo by cultivating close technological contacts between the two peoples, since British oil intrigues in southern Arabian Peninsula alarmed the Sultans.
Only after 10 years, a Congolese force broke though the front for more then just a raid. Durban was heavily garrisoned by state-of-the-art troops, but the Congolese brought more artillery. Congolese cannons were very quickly made in the forges of Kalemie and Sofala, and were ineffective compared to cannons used in most of the world, but Congolese cavalry was well-equipped and in its effectiveness, was comparable to the cavalry of the American Civil War between the Confederacy in the American South and the social-democratic United Socialist States in the U.S. north.
USA didn't collapse, but around that time it experienced anarchy, switching its name from Confederate to the United Socialist States of America
Natal was freed thanks to brave warriors of Congolese cavalry and the hard-working toilers of Congolese forges. Yet the rest of British South Africa was defended well, as the British introduced aerial-based warfare to the military theater. Congo had no airforce of its own in this time, and constant aerial raids on Congolese positions on Durban were very harmful to the Congolese morale.
During these times, a French admiral docked in Congolese port next to Mbanza Congo, and started shelling the city, demanding a financial contribution as a payment to leave the coastline alone. The Congolese Republic had to give in to this arrogant act of blackmail.
Technology exchange with Arabia continued.
While the South African front was relatively uneventful, the British blockaded Congolese coastline. Daily aerial bombardment from the sea, while not particularly harmful for the Congolese Republic as such, brought a lot of suffering to the local population. "The Tragedy of Mbanza Kongo", depicting the horrific effects of British bombings, written by an anonymous Congolese playwright, was considered to be a classic of Congolese literature for a long time.
Congolese-produced rifles were better then the ones produced in certain European nations, Scandinavia in particular. Since both Congo and Scandinavia were fighting the British, military cooperation between two countries was established, with Scandinavia exporting its new artillery to Congo. That was just the weapon needed to crush the British.
In 1919, British South Africa was no more.
The Congolese government hired Chinese pilots to start Congolese Air Force, sending industrialists to China in return.
Many big English landowners in South Africa refused to submit to Congo. They proclaimed themselves to be under the Dutch patronage.
Congolese army easily completed the liberation of South Africa by kicking the Dutch troops out. All land previously belonging to the big English or Dutch landholder oligarchs was divided and given to native hired labor.