I had someone place an order so that I would format his book. I delivered once and he requested a modification for some things. No problem, I opened the file again and modified the work and did exactly what he wanted me to do but now, for like 10-11 days straight he keeps requesting a modification and says something along the lines of “I will keep doing this so I’m good” and something like “You won’t receive the money”. I honestly have no idea what is going on. He requests a modification almost 3-5 times a day. What can I do to finally have the order completed as marked?