brake's squealing and grinding noise...

[BFD83]

hey guys, the front brake pads on my car are really giving me the s**ts!!
i got new pads put on back in dec last yr, the discs were machined and everything and they were great for the first few weeks, then all of a sudden they just started to squeal everytime i would put my foot on the brake..i've just been to lazy to go back there and get em to fix it. my uncle who is a mechanic looked at them on sunday and he said they are fine and that i shouldnt fork out money just to fix a bit of noise, but not only do they squeal they also make this weird like grinding noise..im really not sure what it is but im sure its something to do with the brakes cauz it only does it when i brake. they werent genuine ford brake pads i got put on and was told that i should have got them on cauz they dont squeal. can anyone help me and tell me what i should do cauz the noise is driving me insane!.