Log entries like the following mean that no corresponding transaction could be found in Magento for the Directlink request.
2014-04-10T09:10:29+00:00 DEBUG (7): Run into exception 'Warning, transaction count is 0 instead of 1 for the Payid "...", order "294" and Operation "capture".' in directLinkPostBackAction
This can occur when the merchant changed the status of a transaction in the Ingenico backend, or if a refund has been issued there instead of from the Magento Admin Panel.
The correct procedure is to trigger all transaction changes or refunds from the Magento Admin Panel only.
To make a refund, make sure to follow the correct workflow, see this article.