Vauxhall Vectra boot cant open

Hi all, my dad has a vauxhall vectra 1.9 cdti brought only 2 weeks ago and where he used to be able to open the boot he now cant. On the dash it says its open but it remains closed and unable to open. When the key is in ignition it makes a whirring sound when pressing the button but nothing happens. Any suggestions on what we are doing wrong would be much appreciated, especially as Im having to do their shopping until they can get it open!! THanks all