False advertising

In June 2019 I signed up for their 4mbs ADSL package which included a free router and Wifi range Extender. I received the router and have installed it. I never received the wifi range extender! After repeated requests telephonically and via email,I have been informed that they don't have stock! No stock for the past 6 months ???? Don't advertise something for free when you know very well you cant deliver!