The story of Amos Vilakazi, a tuck shop owner from Soweto who has successfully run his business for 20 years, ought to be an inspirational case study in entrepreneurial resilience.

But Vilakazi's story has turned into a tragic tale familiar to many small business owners, especially in townships and rural settings across the country. His business has been pushed to the edge by a crippling nine-month blackout that is now threatening his family’s livelihood...