If someone is using your WiFi connection without your permission, you can easily block the user from your Wifi network. This video shows, how to block a device from Wifi in your TP-Link router. I'll show you 3 different ways to go about that.
Download TP-Link Tether app
Android: https://play.google.com/store/apps/de...
iOS: https://apps.apple.com/us/app/tp-link...
Intro 0:00
Block a Device using TP-Link Tether App 0:13
Block Users through Access Control 1:20
Block Devices through MAC Filtering 3:04