Mobile phone operators today denied deliberate overcharging customers after three separate scandals in the last six months.
Representatives from Vodafone, O2 and Meteor appeared before the Oireachtas Committee on Communications in Leinster House.
O2 admitted in June that it had overcharged 70,000 customers for roaming charges and days later, Vodafone said it overbilled 22,000 customers to the tune of €147,000.
Earlier this month, Vodafone said again that it had overcharged 550,000 customers for WAP services over the past year and a half.
Labour TD Mr Tommy Broughan tonight said he was "a bit stunned" when he learned of all the revelations.
O2 Ireland CEO Ms Danuta Gray said: "There is no deliberate overcharging. We have the same system (as Vodafone Ireland) and errors can occur but we've spotted them."
However she admitted that O2 "did not communicate early enough" with customers as its roaming overcharging problem was discovered in late April but was not publicly announced until June.
Meteor Ireland's director of public policy Mr Andrew Kelly said: "There is no deliberate overcharging, certainly not on the part of Meteor and not in the industry in this country."
The Committe heard that Ireland's young population meant that 90 per cent of people have mobile phones compared to just 50 per cent with fixed land-lines.
O2 and Vodafone share about 93 per cent of the market while Meteor has the remainder, but is growing rapidly in the pre-paid sector.
Hong Kong-based operator Hutchinson will be entering the Irish market in early 2005.
Committee members agreed that tariffs and bills were often too complicated for customers to understand and that high profits enjoyed by Vodafone and O2 should mean prices fall more dramatically than they were.
Committee chairman Mr Noel O'Flynn said that roaming charges should be explained better to customers.