Virgin Mobile South Africa is complaining that the country’s big two cellcos are blocking attempts by customers to switch networks and take their number with them. Mobile number portability (MNP) was introduced in South Africa earlier this month and initial indications showed that demand had been poor. MVNO Virgin is now claiming, however, that subscribers of Vodacom and MTN are having difficulty switching providers, with up to 80% of transfer requests refused. Business Day quotes Virgin Mobile’s head of corporate affairs, Nicholas Moweni, who says that thousands of requests are turned down because customers owe money to their existing provider. MNP regulations state that transfers cannot be blocked over non-payment of bills unless the problem is so serious that the customer’s account has been suspended.