The sudden airtime losses experienced by MTN subscribers last Friday was a result of a system error. The problem affected mainly clients with Internet-enabled phones, Yvonne Makolo, the telecom’s marketing manager, has said.

She, however, said the system has since been fixed and customers refunded the money lost on Saturday and Sunday.

"Anyone who hasn’t yet been refunded or was partly refunded should send us a message through our social media platforms or through the call centres and we refund them immediately,” she said.

Subscribers had complained that part of their airtime was missing before they could use it.

"I loaded airtime of Rwf30,000 and within a few minutes I found only Rwf20,000 yet I hadn’t used it,” said a subscriber who preferred anonymity.

Some complaints were let out by the subscribers on the firm’s official Twitter account.

Jean Baptiste Mutabazi, the head of communication and media regulation at Rura, in an interview yesterday, said MTN had informed them about the issue and "are waiting for a detailed report from them on what went wrong with their system”.

"Normally, when we receive such complaints, we instruct the operator to inform the public and sort out the problem right away. Otherwise, the systems and infrastructure do not always work at a 100 per cent,” he said.

Meanwhile, MTN yesterday reported that the fibre link, via Uganda, is down which may cause internet slowness. "We’re working on the issue and apologise for the inconvenience,” the telecom wrote on Twitter.