Seeing how much these companies lose and throw more money at to gain market share means you won't get more tax. Their revenue might be that high but not their profits.
What you should target them with is (1) anti-competitive behaviour and (2) employment rights for drivers. They have completely abused all systems and their drivers to get where they are but they are probably not breaking tax laws. It's an unsustainable model.
On the other side, the likes of McDonalds gain massively from the extra sales and probably do lots more of the dodgy stuff tax wise...