The Barbados branch of Cable and Wireless (C&W) is attempting to recover thousands of dollars lost in a scam which allowed clients to make free international calls.
Cellular telephone users on the Caribbean island found if they punched in *89 after dialling overseas telephone numbers they could talk for hours without the call showing up on their bills.
The British company has lost nearly 1m Barbadian dollars ($500,000) due to the loophole which has been going on for months, the Associated Press reported, although company officials said they believe the figure to be far lower.
"It is our intention to recover all the money owed," said C&W spokesman Peter Eustace.
Contacting customers
The company would not say how it discovered the problem, only that it had been corrected.
"Our local business will be contacting customers impacted by the use to discuss payment," the firm said.
"It will be using usual credit management processes to recover the debt."
The company would not comment on how many people made the calls but said the scam was only employed by a "small section of its customer base".