The Association of Licensed Telecom Operators in Nigeria (ALTON) has officially announced the withdrawal of USSD services it provides to Deposit Money Banks (DMBs). The association said the reason for the withdrawal of the services was due to over N120billion owed members by the deposit money banks. It added that the level of debt was no longer unsustainable given the time/value huge cost of the continuous upgrade and operation of the systems and infrastructure dedicated to supporting USSD transactions.