Many moons ago those stores were "Customer Service Branches", effectively a One Stop Shop where you could do all your business with a Telkom representative. These branches were all over the country, including many smaller towns.
Then Telkom decided to change them to a "Sales" channel and even tried to prevent customers from paying their Telkom accounts at the stores! A "hotline" was installed in a corner and, if you were not buying something, you were pointed to the "hotline" to do your business via a Call Centre.
In short, they became Client Disaster Zones. They would NEVER be "profitable" in pure financial terms - their worth was in establishing rapport with customers and ensuring that every visitor left the branch happy!
See the direct link to the proliferation of Telkom Call Centres?