Someone could have official terms and conditions with proof about the date. Such as for example receiving them by email or having them archived on a reliable website.
When it comes to reliable site for archiving of such data then I guess Archive.org's way back machine could be the most reliable site to search for old archived pages of the sites. You may try to search there and there's chance you might find something there. However, I think that you're searching about terms and conditions of 2021 and that's why there might be some inconsistencies or errors whatsoever.