wow @slobberchops, this sounds so shady, I do receipts on the job, customers can have one either in paper or electronically it is up to them.
£250 for 3 dudes and 4 hours might be about right, as the price to dispose of green waste at the minute is £195 per ton. that is if it has even made it to a green waste center.
£20 per hour for the first guy, and £10 per person as a laborer for 4 hours is £160 then depending on the waste weight to dispose of it, could be around the £250 mark.
Sometimes a skip can be cheaper, but that is depending on the price at the time.

As long as your happy with the job that they have done mate and your happy with what you paid then that's the main thing. :D