They come after the business upgraded its billing system to make it easier for customers to understand bills and to manage their accounts online.
Islands Energy Group CEO Jo Cox said only a small percentage of customers was affected, but it did not know the exact number.
‘Unfortunately, there have been some teething problems with the system, which has resulted in some people either not receiving a bill, having direct debits taken from accounts without corresponding invoices arriving on time, or not receiving invoices for some considerable time,’ she said.
‘We know this is not acceptable and we are taking urgent steps to rectify these issues to ensure our customers get the most benefit from the investment we have made in the new system.’
She said in most cases the problems were with the bills, rather than how much was paid.
‘For example, if a customer pays by standing order, the credit may not have appeared correctly, but it has been added to their account and will be present on their next invoice,’ she said.
‘There have also been some instances that we are aware of where a bill may be estimated, or an incorrect amount has been shown.
‘We are working through these errors as a priority and will correct them as quickly as possible.
‘I am also aware that due to these ongoing issues it has been very difficult to get through on our phone lines.
‘I understand that it’s incredibly frustrating not to be able to speak to someone, so we have provided more staff to answer calls and are working through queries as quickly as we can.’
If customers do believe their bill is wrong, they should call the customer services team on 724811.