SYSTEM WORKS COSTINGS INCORRECTLY

We have called the SAGE ONE ACCOUNTING support line numerous times as the system is working out our average costings incorrectly. The support team have been unhelpful and as far as they are concerned they sent a suggested solution which is incorrect. We have asked to speak to a developer and have been told to send an email. We were told to email a manager. We are frustrated as this is impacting our financials, time and having to work out the costs of our goods manually. This should be a standard and reliable function of any accounting system.