Motorite extended warranty is not reliable

I purchased a second hand car in January this year at mom motors and bought a 2 year mechanical warranty along with it, from Motorite. The car was due for a service end of September, and from the service they found that the brake discs and pads are worn and the clock spring too. My claim for these components was denied because it’s part of the items that aren’t covered. I dont understand why these components are not covered because they are mechanical components, what exactly than, is covered? Is there even a need to buy this extended warranty if I’d doesn’t cover even half of the components that could have problems?