Inspired by this question where individuals can't imagine something being possible, and somewhat similar to this.
I've recently been in a debate where the debater had the very annoying habit of just point-blank denying the existence of points, quotes - including quotes of their own posts - or facts, whenever the information inconvenienced them, simply declaring that I hadn't provided any factual evidence whilst then introducing an off-topic red herring.
When initially making points, references will be supplied (or the quote a line very recently said, IE previous reply), however due to the medium of social media with character limitations, it's not possible to continually re-reference multiple points via URLs that take up precious limited space.
Classically, debates have it so the burden of proof is on the person proving it, however, if a person does supply the proof, what does one do when one encounters an opponent who continually denies the existence of supplied proof?
Are there any rhetorical or informal approaches for handling this?