Three Ireland has issued an apology to all customers who might have received charge notices for non-existent roaming data usage.
It is understood that many users began reporting receiving text messages to say that they had spent money on roaming charges when in fact they were not abroad.
The company admitted that an IT update blunder caused the issue, which Three Ireland said it will be rectified soon.
Prepay customers are due to receive their refunds by this evening, while those on bill pay will have to wait until the next billing cycle.
Were you affected by this issue? Let us know in the comments below.