Returning Modem and TV Box

Hello, 

Last year I ordered TV and Internet subscription that includes 2 wifi boosters. Now I switch to a different provider, I am returning the old equipment. I have a question though. Do I need to return my wifi boosters as well? According to the mail came with the return box doesnt mention the wifi boosters. Checking my products via kpn web site, I didnt see with respect to this.

Kind regards,

Yigit