I've had that happen to me. I commissioned a razor with a switchblade type mechanism in it (like this
), and got a quote, sent the money and had pretty good communication between me and the commissioner. But 6 months after sending the money, I still didn't get my razor. I kept emailing the person asking when they were sending my razor out, they occasionally responded with emails such as "Oh I'm so sorry, I meant to send it today, but I forgot..." or "I've been away for a while and haven't gotten around to sending it..." and then pretty soon they just stopped responding at all. It's been 2 years, and I still haven't gotten my razor or heard from this guy (I messaged him on his YouTube account as well). So I am assuming I will never get my razor.
Part of me thinks that he thought he could make what I wanted, so he took the commission, but then realized that it was really hard to make, and couldn't be bothered to tell me that. So he just never sent anything out. Or he is a desperate prick who just wanted to steal my money. I think it's probably a mix of those two
So now I am more cautious with who I commission from, I now (for the most part) only commission people who have websites set up and examples of their work and who reply in a timely fashion. I have sent inquiries about commissions to many people, and usually after the 3rd email correspondence with them, they kinda just stop responding, so that tells me that they didn't really want to do the commission or they didn't have the ability to do it, so I just search for a new commissioner then. This is the reason why my cosplay took so long to get together. It was hard to find a decent commissioner.