The Wikipedia citations cannot easily be checked (since they are all in hard copy books).
However, I managed to access one of the citations (Tesla: Man Out of Time) via its Google Books preview. It also makes a far weaker version of the claim, since it also quotes Edison's supporters denying that he had made that statement, instead saying that the payment was in exchange for purchasing one of Tesla's patents. The citation given (Citation 10) was inaccessible through the Google Books preview.
This unsourced Reddit comment also asserts that he could not find citations that Edison actually scammed Tesla while making that quote.
There is no mention of Edison uttering 'you dont understand american humor', or at least I cant find any. It should be important to note that Edison, while being an inventor, ran a business. Most of his actions (that have polarized views right now) as a result, need to take this into account.
A later comment in the same thread claims that it was not Edison, but a manager at the company who made that statement.
Again, this ascription was never made by Tesla himself in any recorded medium. He names only "The Manager," whom people took to be Edison. But Edison wasn't the manager; as I point out every time this comes up, Samuel Insull was in fact though Charles Batchelor had the title. Insull really, really disliked Tesla, and such a thing was within his personality; Edison expressed no such animus.
Did Edison refuse to pay Tesla, and did he make that statement (or any other similar comments)?