KFC
Refusal to give a tax invoice again

This is the second time I went through the KFC Brackenhurst drive through where the cashier refused to give me a VAT invoice. There used to be a sign on the window stating if no invoice is given the meal is effectively free. However today there were no signs and no phone number. It happened at about 4h20pm 18Aug2013. To add to that the cashier gave me a 330ml can instead of a 500ml bottle (which was rectified thank you).
Not providing a VAT invoice is illegal, but I wont take this matter further than this. Please do not contact me.