What was the worst client/boss experience you’ve been through?

I’ll go first. I was in a rut. No clients, no prospects and no jobs. Someone saw my work, really liked it but didn’t have the budget. I dropped my rate to about 40k to just pick up the project. They paid me 50% advance (20k). The project lasted 2 months with atleast 5 client visits (each round trip costing me a little more than 1k) I made multiple design options over several weeks. After one of my presentations, I was about to hop off the zoom call when I heard one of the partners of the firm say “This is really good, very sharp work. Exactly what we wanted”. I wasn’t supposed to hear this because they felt I had dropped off the call. I felt good that they liked the work. I wanted them to be super happy, so I went to print shops to get multiple color samples for them, made PPT templates (it’s really annoying and painful to make one of those), made tutorial videos on how to use different elements, how to use the templates without breaking them, getting on calls with his team to teach them etc (all of which cost me time or money or both). I finally got to a place where everything was sorted. All the files were handed over along with proper documentation. Once done, I asked for the rest of the pay. And the client told me that he’ll only pay me if I get his visiting cards printed! This was never mentioned anywhere till now. I told him I could do it for an additional charge (what the printer would charge me, I even excluded my cost of going till the printer and back), but he just stopped responding. I followed up multiple times but didn’t get any response. Not only did I make a loss on the project, it was a project where the client was actually super happy with the work. Felt really bad and annoyed that I had gone out of my way to make the client happy and he couldn’t even do the bare minimum of paying me for the work I did (and that too the discounted rate 🙄) The bittersweet ending: They are still using my work that was done about 5 years ago.