My father is a locksmith so i know a small bit about the trade.
First of all does the car have an immobilizer?
Is the car open?
i warn you not to panic as most people do in this situation by either breaking a window or trying to prise open the doors, but the tuth is it gets you nowhere in the end. Just be calm about it. If the car does not have an immobilizer you can get this fixed cheaply by geting a key number from your V5 or else just going to a local VW branch and giving your chasis number.

But if the car does have an immobilizer you will have you get a key number anyway, this will mean you can get a key cut for a few quid that will open the doors but will not turn the ignition. You will then need to get the key coded into the cars ECU.

Get back to be and know how you get on.