2007 Toyota RAV4 wheel/brake noise

Brakes problem
2007 Toyota Rav4 4 cyl Four Wheel Drive Automatic 82000k miles

I recently purcchased a 2007 rav 4 and am experiancing noise from the front wheels/brakes when brakeing, when we bought the truck the brake pad was soft and went to floor, the dealer said they would check all brakes and make like new, well I picked it up and it was still soft and after fighting with the salesman / owner that something was wrong with it ( I even had them bring another rav4 beside mine and showed them the differance) he had service look at it and they found nothing wrong, even suggesting that maybe the other rav4 was the one not working properly, I stood my ground and demanded that they keep truck till fixed, turns out the mastercylinder needed replacing, (the first time this mechanic has seen one fail)well this went fine for couple of days then this noise starts in front right wheel when braking, a kinda scraping / grinding noise that seems to be timed with the tire rotation when coming to a stop. I took it back and they said it was the grease that is put on brake pads when installing new ones and they would clean up and put more on, I had my doubts but. Happened again they said because mech. Never cleaned both parts when he repaired it it happened again, I asked what next they said clean up both sides and apply grease again and if that doesnt work there is a shim package for pads also, I had them put shims on and clean and regrease and guess what? Its happing again! At first it only happened after driving for awhile, now its when ever you are coming to the end of braking, just the last 20 ft or so especially when going down a hill. ( I wonder if a disk is warped or something, should disks be faced when brake pads replaced? ) Any help would be appreciated I have appointment next week & am sure they are not looking forward to seeing me as much as I not wanting to see them