Explain them that the software you sold him/her ten years ago is not the software you sell today.
But in the end, some people will just try and get free stuff. Just tell them that doing business with you has a price and that otherwise they can bring their business at someone else's shop.
But in the end, some people will just try and get free stuff. Just tell them that doing business with you has a price and that otherwise they can bring their business at someone else's shop.