Ban error

Code van de ban:
------------------
    if (command === `${prefix}ban`) {

        //!ban @TAG reden hier

   var banUser = message.guild.member(message.mentions.users.first() || message.guild.members(arguments[0]));

   if(!banUser) return message.channel.send("Gebruiker is niet gevonden!");

   var reason = arguments.join(" ").slice(22);

   if(!message.member.hasPermission("MANAGE_MESSAGE")) return message.channel.send  ("Sorry jij kan dit niet doen.");

   if(banUser.hasPermission("MANAGE_MESSAGES")) return message.channel.send("Deze gebruiker kan je niet banen!");

   var ban = new discord.RichEmbed()
   .setDescription("ban")
   .setColor("#FF6A00")
   .addField("baned gebruiker", banUser)
   .addField("Gebant door:", message.author)
   .addField("Reden:", reason);

   var banChannel = message.guild.channels.find("name", "discord-bans");
   if (!banChannel) return message.guild.send("Kan het kanaal niet vinden.");

    message.guild.member(banUser).ban(reason);

   banChannel.send(ban);

return;

}

---------------------
ERROR: Wanneer ik !ban @een speler reden doe

[nodemon] restarting due to changes...
[nodemon] starting `node index.js`
De file close.js is geladen
De file hallo.js is geladen
De file leave.js is geladen
De file pause.js is geladen
De file play.js is geladen
De file resume.js is geladen
De file skip.js is geladen
De file ticket.js is geladen
Zuidland Bot is online!
(node:6892) DeprecationWarning: Collection#find: pass a function instead
(node:6892) UnhandledPromiseRejectionWarning: TypeError: message.guild.send is not a function
    at Client.bot.on (C:\Users\kianv\3D Objects\ZuidlandBot\index.js:133:42)
    at Client.emit (events.js:197:13)
    at MessageCreateHandler.handle (C:\Users\kianv\3D Objects\ZuidlandBot\node_modules\discord.js\src\client\websocket\packets\handlers\MessageCreate.js:9:34)
    at WebSocketPacketManager.handle (C:\Users\kianv\3D Objects\ZuidlandBot\node_modules\discord.js\src\client\websocket\packets\WebSocketPacketManager.js:105:65)
    at WebSocketConnection.onPacket (C:\Users\kianv\3D Objects\ZuidlandBot\node_modules\discord.js\src\client\websocket\WebSocketConnection.js:333:35)
    at WebSocketConnection.onMessage (C:\Users\kianv\3D Objects\ZuidlandBot\node_modules\discord.js\src\client\websocket\WebSocketConnection.js:296:17)
    at WebSocket.onMessage (C:\Users\kianv\3D Objects\ZuidlandBot\node_modules\ws\lib\event-target.js:120:16)
    at WebSocket.emit (events.js:197:13)
    at Receiver.receiverOnMessage (C:\Users\kianv\3D Objects\ZuidlandBot\node_modules\ws\lib\websocket.js:789:20)
    at Receiver.emit (events.js:197:13)
(node:6892) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:6892) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
(node:6892) DeprecationWarning: Collection#find: pass a function instead