The "PaperSize" property of the figure affects only PDF and PostScript file formats while saving the figure. Hence, when you are trying to save the file in EPS format, the "print" function ignores this property.
This is documented under "PaperSize" figure properties. Refer the link given below: http://www.mathworks.com/help/releases/R2016a/matlab/ref/figure-properties.html#prop_PaperSize