I have seen some reputed casinos lagging in this aspect. They make you wait days for a reply to email. There live chats makes you wait for hours. Thus, it makes sense to check the customer support by sending mails or trying live chat before you join the forum. How important is customer support of an online casino for you ?
Just imagine a real casino like Wynn or MGM or any business in this world without customer support? That is just the same with online casinos. There got to be people preferably live chat in order to assist and answer people needs.
Late replies are understandable sometimes especially on delicate cases where reviews are necessary.