Some were told that the bill was for exceeded their data plan, but as the 1GB limit is only a "fair use" recommendation the worst one should receive for exceeding it is a severe telling off.

When we contacted 3 we too were initially told that no problem existed, though it has now accepted that something went wrong. Heavy data users who received a bill in the last week might have been over-charged for that data. The problem has now been fixed, and 3 says it will call up everyone who was overcharged to arrange a recalculated bill, or a refund if necessary.