Bank card has been charged twice?

Go back into Argos with the doentary evidence that the charge has been taken out twice. refuse to budge until you get an urance from the manager that youll get a refund. While you are there, if they get stroppy, talk in a loud voice to all who will listen (and those who wont) about how bad the service is, how they cant be trusted to be honest, how youll report them to Trading Standards. This worked for us in the computer game shop.