Are you using an icecream maker? Sometimes with some icecreams the additives like cocoa help reduce the icyness.  Some people add malt extract to their vanilla icecreams, this helps reduce the hardness of the icecream.  But what you can do if you don't have an icecream maker, it may be a pain in the butt but end result should be good, every 2 hours or so take the ice cream out and beat it (probably best with an electric mixer).

Thanks for replies.   I have experimented with the glucose syrup in vanilla ice-cream and am having some success, it seems to work well, I am still adjusting quantities of syrup and dextrose