Translation:We talk and talk and they do nothing!
Just a nitpick, but כלום does not mean nothing. It means "an extremely small amount". But most people don't know that.
It actually means 'something' according to this article: http://hebrew-academy.org.il/2012/08/08/כלום-ושום-דבר/
True, so לא עושים כלום is not actually a double negative. But in spoken language כלום is used as "nothing", for instance: what are you doing? כלום.
I was taught in biblical hebrew that prefix vav can also act as the "but" conjunction, not just "and". Would this apply to modern hebrew too? Seems a bitter translation here to me.