How much electric left on this meter?

Hi
Has anyone seen this type of electric meter? It has the normal dial (on the left) and it has a card meter added. The card meter, I think can only read £1 cards.

At the moment, it will not accept any new cards. Apparently you are supposed to insert the card, when the red light goes green you are supposed to press the button and turn the dial. The red light won't turn to green (so pointless pressing the button) and the dial won't turn. The tenant says when he turned the dial he heard something drop inside.

A new meter has been ordered but the tenant is worried he's going to run out of electric before the new meter is ftted and set up. There's a number of rooms in the bedsit that use this type of meter and no one knows how to read them so they normally end up running out of credit.

If you need more information then please contact me.

Thanks

Colin