I wouldn't have gave it to them!

Is 5 hours a long time for a portrait? You shouldn’t have sold it to them. Sell it by other means. It’s your work.

Yeah, I have had the same problem. Someone asked me to do a portrait of her dog then watched me pencil sketch the whole thing and when it came time for payment she said it was too big. Then she watched me weep in frustration. People are fuckers.

You should go all Jackson Pollock on that shit and smash the canvas over that crook's head!

They agreed to $300 for a portrait, they pay $300 for a portrait. The only way I could possibly see not paying full price is that either you were late with the work or screwed up somehow. "Too vibrant" is horseshit and you should have made them pay the full price or found a different buyer who would appreciate the effort and work involved.

If they do not pay the agreed price they do not get the product.

Contracts. Use them. Live by them.

Yeah definitely a contract, or some kind of pre painting agreement. I know you needed the money, but you can’t let yourself be scammed

What a shame! All work is deserving of fair payment, and the work that an artist does is so far beyond whaT most people do when they work. You asked a more than fair price. I hate to say it, but you may have to do like some have suggested - resort to contracts that stipulate the price and that the buyer does not get possession of the work until full payment has been made. Good luck, OP!!

They would not get the painting until the agreed upon price.