[Kindred]

I honestly have no idea how I didn't see it before.

pawn Код:

dcmd_setfaction(playerid, params[])
{
    new giveplayerid, amount;
    if(sscanf(params, "ud", giveplayerid, amount)) SendClientMessage(playerid, 0xFF0000AA, "Usage: /setfaction [playerid] [factionid]");
    else if(giveplayerid == INVALID_PLAYER_ID) SendClientMessage(playerid, 0xFF0000AA, "Player not found");
    else
    {
        new name[MAX_PLAYER_NAME], file[256];
        GetPlayerName(giveplayerid, name, sizeof(name));
        format(file, sizeof(file), SERVER_USER_FILE, name);
        if(!dini_Exists(file))
        {
            SendClientMessage(playerid, 0xFF0000AA, "Player is not registred");
        }
        if(fexist(file))
        {
            PlayerInfo[giveplayerid][pFaction] = amount;
            dini_IntSet(SERVER_USER_FILE, "Faction",amount);
        }
    }
    return 1;
}

You are getting the name of playerid, not giveplayerid, and your setting playerid's faction to the factionid. I just changed it to giveplayerid so it would set the actual players faction.