Turbowifi is confusing the public by using the term wifi and internet interchangeably. Wifi is a local technology used within a confined space i.e. your house. The Internet is a global technology used to connect your wifi to the world. Turbowifi is one of many wifi range extenders sold by many tech companies. You cannot increase your internet bandwidth because you don't own it. You can extend the range of your wifi within your house or property. Turbowifi is really using false advertising if it claims to increase your internet bandwidth.
As for the router manipulation issue, if you bought your own router and installed it yourself. Any ISP would have to have your password to change any router settings. If they provided the router, then yes, maybe able to manipulate it. Internet bandwidth isn't delivered in "channels". That only takes place within the wifi of your home. Turbowifi doesn't really do what it says in their advertising.