Systems had been established to resolve queries within an acceptable time-frame and the integrity of statements sent to customers had been improved, spokesman Gabu Tugwana said.

He said this was in line with the Roadmap for Revenue and Billing announced in November 2011, when the City committed to improve its customer service.

"The backlog of customer queries were successfully resolved by a dedicated clearing team by the end of June," said Tugwana.

He said outstanding queries were those reported in fewer than 30 days.

"Adequate resources have been allocated to identify and deal with any additional, complex issues which may as yet not been resolved," he said.

Tugwana said a quality assurance mechanism had been set up where resolved queries were checked for accuracy before feedback was given to customers.

"We have also initiated open days, where customers are presented with an opportunity to enquire about various services with relevant departments," he said.