It is clearly sitting on the balance sheet in "Intangible assets". If you read Note 13 you can see the net book amount for computer software was $13.425 million at 30 June 2016. I think it's pretty inappropriate to suggest the costs are 'buried' when they are clearly identified in the financial statements.
Also there should be no need to write off the entire amount. I suspect this write off is a result of Rivas coming in and improving processes rendering some of the existing computer software redundant - hence the need to write it off.