He never went through with replacing the doll and we have no idea why. Jin's "official" reason is that "Twilight" prefers the deformed doll, but of course no one buys that. Here (
http://buttercupbabyppg.deviantart.com/art/Plushie-Twilight-Club-499561769) Jin claims one of the plushies is his and that he'll be contacting the maker about the final price. Jin claims that someone's death fucked around with his savings, but to be honest I think he's lying. I think he was trying to get sympathy in order to pay less for it, but the maker didn't go for it so Jin wound up not getting it.
As for why he wouldn't pay for this after paying over $400 for the deformed one, Jin has been well documented to be horrible with money. He probably drained his tugboat (or whatever his source of money is) with any number of stupid expensive purchases and fucked himself over with the plushie.
It's also possible that the maker found out about how openly Jin fucks the thing plus all his other gross fetishes he practices on his deformed doll and refused to have their work associated with him. It even could be that Jin never intended to buy a new plushie but pretended to for whatever reason and just left a comment on a picture that didn't identify the commissioners as part of his lie.