"Today, I will give this cast-iron guarantee: if I become PM a Conservative government will hold a referendum on any EU treaty that emerges from these negotiations. No treaty should be ratified without consulting the British people in a referendum."
See that last bit? That's the bit which people conveniently ignore - presumably deliberately, because it doesn't fit their argument. Think about those words - "No treaty should be ratified"... let me spell it out for those who have their fingers in their ears and are shouting 'la la la, can't hear you'. No Treaty Should be Ratified means that a referendum should be held IN ADVANCE of a treaty being ratified.
So again, I issue the challenge: show me where David Cameron has ever promised a post ratification referendum, You can't, because he hasn't. He has consistently said that he would not let matters rest there. And yesterday he explained how.