The refund part was actually a cake walk/waiting game. I went through Paypal's disputes center because the period of calling for a refund is a lot longer than I was led to believe, and after a period I was able to escalate the dispute to a claim. Due to a lack of response to the outreach from Paypal by Mothux, I kind of just had to wait for the days to come and go.
When Mothux posted in May of 2020 that they were opening for a few pin-up slots; I had a steady, disposable income; and their art style looked slick- -I jumped right in and ordered a pinup from them. After this I paid the invoice they sent me and began to wait. I added them on discord 9 days later, and we both said hello. I played in some small talk to get conversation going because they hadn't responded to my question about additional info in almost a week, and I got a response then. After that, it was crickets.