After attempting to reach out to a client for 3 months through various forms, with no response, I sent an invoice for a logo design (that had been done 4 months prior).
Client: (yelling) I don’t know why you’re sending me an invoice now. Why didn’t you just send me an invoice when you started? I haven’t even used the logo yet!
Me: I have been reaching out to you for 3 months and you haven’t responded. I figured the job wasn’t going anywhere so I thought I’d settle up for the work I did do.
Client: I still have things I want you to do!
Me: Well, I still spent hours working on this logo, and the last I had heard from you was 4 months ago, so…
Client: But I haven’t even used it on anything! Why are you billing me?
Me: At this point, I’m not even sure.
I eventually gave up, because getting paid would be more effort than doing the logo on the first place.