Grinding problem

I did a quick search for an answer and to be honest I don't think I understand cars enough to know exactly what to search for, so please bear with me.

My car has a grinding/squeaking noise at times when I brake and sometimes at turns both slow and fast coming from what sounds like my front tires. That being said, I have had both front and back brakes done and checked and also due to various servicing (transmission checkup..automatic by the way, back brakes being replaced, "major" tuneup and complete set of new tires + front end alignment) I have had at least 3 free brake check ups, had my axles checked a few times and no one has found anything out of the ordinary or mentioned any reason that I would have such grinding/squeaking noise coming from my wheels or underneath my car.

Any advice would be helpful as to what this noise could be. Especially after all the services and various checkups I've had, I'm certainly getting frustrated and want very much just to have the car running normally without the grinding/squeaking sounds.

Thanks.