Open the chat with the bot and use Stop Bot, or block it. Either one ends the messages immediately, and neither requires you to contact anyone.
Stopping it
- Open the chat with the bot.
- Tap the bot's name at the top to open its profile.
- Choose Stop Bot. On some versions this appears as Block Bot.
- To remove the conversation as well, go back to the chat list, swipe or long-press the chat and delete it.
If the bot is messaging you from a group
A bot in a group is there because an administrator added it, so blocking it in a private chat will not quieten the group. Either ask an administrator to remove it, or mute the group so it stops notifying you. Muting is under the group name at the top of the chat.
If it approached you first
A bot cannot normally message you out of nowhere. If one did, it is worth reporting: open its profile, use the menu in the corner, and choose Report. Unsolicited messaging is one of the most common reasons bots get restricted, and reports are how that starts.
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