I want it for argon....lolMost recycling centres have gas cylinder cages and will take old cylinders but they may make a small charge for the service.
I would think that the filler would have no record of when the cylinder was last tested, it might have failed a test and been binned, or what its been previously filled with, they would have to test it before filling, which would cost you. I'd say that no one will legally fill an unknown cylinder ?