MTN has investigated a report of disappearing airtime on its network and found the cause to be an issue with its SMS charging system.
An MTN customer recently contacted MyBroadband after noticing that his airtime balance was decreasing, despite him having active voice, SMS, and data bundles.
The customer recorded his MTN airtime balance over a 10-day period and found that his balance was depleting at a rate of around R0.10 per day.
This resulted in a total loss of R1.00 over the 10-day test.
Additionally, out-of-bundle data usage was not active for the user.
Faulty SMS charging node
MTN executive for corporate affairs Jacqui O’Sullivan said the depleting airtime was caused by a problem with an SMS charging node.
“Upon our investigation, we have established that our customer’s airtime was incorrectly depleted due to a faulty node which is used for SMS charging,” O’Sullivan said.
“The number format for the B-number was not being normalised to 083 format, but was instead being sent as 2783 which resulted in incorrect charging.”
“This node is one of eight which is used in a round-robin method for SMS charging,” she said.
O’Sullivan added that the node was detected and removed from traffic on 20 December 2019, which is why the customer’s airtime remained unchanged from this date.
It is currently unclear how many customers were affected by the faulty SMS charging node, but MTN is investigating this to determine which users to reimburse.
“We have extended our investigation to establish the number of customers that may have been affected by this error,” O’Sullivan said.
According to the mobile operator, the error affected SMS services for a number of its prepaid and hybrid customers.
“Pending the outcome of this investigation, we intend communicating to affected customers regarding their reimbursement.”