The burden of proof is on the claimant (That is YOU) to give that evidence not the other way round. Telling some one to look for that evidence is not 'proof' and it is YOU that needs to provide the evidence.

If it was so easy to prove, you would have already done so in less than an hour. 20 hours is plenty of time to show this proof by now, yet there is none.

There is no shame to admit that you have no evidence and you made a baseless claim.