Heard Sratching Noises When Braking, Changed rotors and Shoes but Still Hearing it

I started hearing this scratching noice when i applied the brakes around last week.. so i took it to the shop and they replaced the rotors and shoes. After driving the car, everything sounded fine for like an hour or so but after that i started hearing the sound again... what could it be??

did water get to it? mine does that too when it rains

They probably didn't apply enough brake shim lubricant or didn't tighten the caliper bolts tight enough...take it back to them and tell them something is still vibrating and emitting that high-pitched squeal (i assume this is the sound you mean).

Pretty much any vibration in the braking system can cause that noise, but if you just got everything changed, then it is probably something minor. First time I did a brake job myself...I had to 'redo' it like 3 times simply because of little stupid stuff like that.