MTN Zambia has been reprimanded by the country's ICT regulator, ZICTA (The Zambia Information and Communications Technology Authority) over its handling of a SIM card registration and validation exercise.

This week ZICTA inspectors paid an impromptu visit to MTN offices after receiving several complaints from customers regarding the exercise.

According to the regulator customers have complained that despite having registered their SIM cards, the operator continues to send unsolicited messages threatening disconnection for non-registration.

ZICTA Technical director services Mofya Chisala who led the inspection said, "We demand that the mobile phone service provider works on its gap in the SIM registration process and avoid sending messages to customers unnecessarily."

Sources within the company allege that data initially received from over 5 million customers has been misplaced, resulting in indiscriminate messages to subscribers.

However, this was denied by MTN Zambia Communications and Corporate Social Investment manager Mwamba Siame.

Zambia's SIM card registration exercise started in 2012 in compliance with government regulation and concluded in January 2014.

Two years later the regulator warned operators they had two months to 'clean up' or update incorrectly registered SIM cards, and the ultimatum was extended to end of June.

It is understood that hundreds of MTN customers remain unregistered and are attempting to register before deadline.

MTN Zambia CEO Charles Molapisi said it was not the intention of the operator to inconvenience its customers and apologised over the concerns arising from the SIM cards registration and validation exercise. "I will ensure that the operator reduces the number of messages it sends to customers," he said.

ZICTA has not indicated what further action would be taken, if any.