The ride-hailing apps were being used by South Africans to schedule and cancel rides in Nigeria as a prank. The apparent motivation for the pranks:
Earlier this month, model ... pulled out of the Miss South Africa contest following public outcry and xenophobic attacks over her ethnicity. [The contestant], who was born in South Africa, was targeted because her father is Nigerian and her mother has Mozambican roots. Soon after, organizers of a similar contest in Nigeria invited [her] to participate in their event, and she accepted.
The incident fueled the long-standing tension between the two countries
From a BBC article with more detail on the beauty pageant:
This was not the first time that this has happened. For ...a Miss South Africa contestant last year, it has brought up difficult memories.
The 28-year-old was the target of the same vitriol heaped on [this year's contestant] because her father is Ugandan.