Let's be honest...
If they sold the same 4G unlimited product (but say 24/7 usage, not that weird 11pm - 6pm) and instead of being R250, it was R1250, towers probably would've been 5x less congested, they would've had far better customer service (because 5x less customers), needed far less staff and probably could've been a bit more profitable and scale accordingly to ensure quality remains constant.
(Just napkin math, take with a pinch of salt, but same concept)
Economically, that's how it should be, considering the demand (thousands of users) is way higher than supply (that one poor little tower) in most areas.
From a budget consumer point of view, it's great that it's cheap and perhaps have a bit of something you didn't have at all prior, so props to Rain for entering that market.... but from a business model point of view, it doesn't make sense / it almost becomes unethical to overpopulate towers like that.
It's kinda like selling 8000 tickets to a concert with only 5000 seats, but promising everyone seats.