Most likely the unit was not set up or hooked up properly, which could be your fault or the dealer's. Pretty hard to say after the fact and I doubt if you will get anybody else to pay without some evidence of what went wrong.
One possibility is that the sensitivity was set wrong for your CRV.
Follow the instructions in the manual carefully and use the Test button to verify all is ok. Also check the car's brake lights before driving off, to make sure they are not on.
If you do not have the manual, you can download it HERE
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL