Game.co.uk - invalid phone number

Hope this is the right place to post but fyi. Ordered some games for kids delivered to sister in London to bring home (because they are cheaper). She got a nice package, nice packing slip, wrong game.

So I went to ring them but the customer service phone number comes up invalid when you phone it from Ireland. Works fine from UK.

Eventually after ringing stores in London and not getting a straight answer if they would swop the games or a number for customer service, I rang a store in Dublin and they will swop over the games for me.