ANSWER:
What kind of a question is this?
If you claim that there is a kaffarah in Ramadan, you provide the muslims with the evidence and not to come and invent something out of the blue and ask people to prove that it is wrong!
It is like claiming that celebrating the birthday of the prophet salla allahu alaihi wa sallam is one of the fundamentals of Islam and asking those who say that it is an innovation in religion to prove it!