Why are my 10 month new brakes making a crushing/grinding sound?

I got a completely new braking system installed in January of this year from Just Brakes. A few months after that they began squeaking. I ignored it which probably made things worse... Now it s the end of Nov. & they are making this loud horrid grinding sound. Why do they sound like this and is this normal? Should brand new 10 month brakes make any sounds? My vehicle still brakes but the sound is gut wrenching. I paid so much money to completely replace my brakes which have a "so called" lifetime guarantee... I m so angry right now!!! Someone please tell me what is going on so I know what to do...