I'm completely frustrated with a client for whom I've done a great deal of work. They ask for one review after another. They won't send me the final work to be edited even though I've asked four times. They keep complaining that they're overloaded with work and have only 1 editor. But, when they do this, they prevent me from getting paid. The editor seems nice but he gives me one excuse after another for not sending the work. Mostly he just says he's "too busy". I don't know what to do. This has been going on for six weeks.