meaning if the screen cracked or broken by itself i can claim warranty? how to proof ah?

and also i wanna know if let said i paid for the premium RM300 for insurance cover my car windscreen. if my car get stolen within same year... do i get back RM300 extra premium which i paid to insure my windscreen with total value of RM2000?

or the RM300 only cover broken but not stolen?
also.. that RM300 extra insurance premium cover the 4 side mirror or not...