It would be impossible for anyone to provide written evidence of such a ban, but I do not feel compelled to provide any proof to this forum. The fact of the matter is he was not able to compete in this year's Mosconi Cup because of a dirty urine test. This is not wild speculation or rumors, but if you want to believe it is, that is your right, of course.
I mean, I could ask Billy himself on Facebook privately, but it would be an uncomfortable discussion, and quite frankly, I don't want to do it. Is that what you need as proof, for the words to come out of his mouth or fingertips?