Thousands of SmarTone mobile phone users were cut off yesterday or experienced problems after a power failure at a switchboard station in Central and Western district.
The problem snowballed after the backup power system also failed after a couple of hours.
Some users complained of losing their phone and internet connections from 11am, while others said they could make but not receive calls.
They complained that SmarTone did not post any information on its website throughout the day, while the customer hotline was constantly jammed.
Some staff at SmarTone branches said they did not know what had happened.
A spokesman for the Communications Authority said the company told it about the power failure at a building in Central and Western district.
'We understand the service had largely returned to normal in the afternoon,' the spokesman said. 'We have asked SmarTone for a report.'