Safaricom has a monopoly. In most countries in the world, no one company unless state controled, does one mobile provider have such a monopoly. Best would be three mobile providers sharing the cake with non having more than 40% of the market share.
It may seem attractive to have a company with a big turnover, but a monopoly leads to less competiotion, less creativity, worse service delivery and in the case of Safaricom here to big time fraudsters.