just to confirm with ian,
i have never known EBC discs to fail because of poor qaulity, its normally other factors, i sell and have sold lots and lots of these discs and loads of there pads and consistently so far touch wood, have never had them come back as faulty.
the couple i have had back were down to user error, thats not to say that there isnt a chance they could be wrong theres always a possibility.
have they done it from day one, or have you been driving them a little hard?
starlet brakes dont take to much to over heat and warp