Wilting is not dead. A Persian violet that dried out hard usually still has live crowns in the middle, so give it two or three weeks before deciding.
The reason one watering did not bring it back: when a peat based mix dries out completely it stops absorbing. Water poured on runs down the gap between the mix and the pot wall and straight out the bottom, and the middle of the root ball stays as dry as it was. So you can water thoroughly, watch it drain, and have watered nothing. That gets read as beyond saving when it is still just dry.
Stand the pot in a bowl of room temperature water about a third of the way up and leave it for half an hour to an hour. The surface should go dark as water moves up. Top the bowl up if it all gets taken. Then drain it properly and put it back on a dry saucer. If even that does not take, tip the root ball out and wet it from all sides in your hands, or repot into fresh mix. Persian violets are fine in a small pot, so that is a five minute job.
Cut the dead leaves back to the base with clean scissors. Do not cut into the crown, even if it looks brownish. That is where the new leaves come from.
Then bright indirect light, not a hot windowsill and not a dark corner. Soil like a wrung out sponge from here on, no more swings. Away from radiators. No fertiliser until you see new growth. Humidity helps, but a saucer of pebbles and water under the pot does it; misting soft foliage invites rot.
Expect it to look worse for the first week as the damaged leaves finish dying, then new leaves from the centre from about week two or three. If the middle of the crowns is still firm and green there is something to work with.