Phone damages with apple case

Whether in a case or not, if dropped the front or back glass can break. Apple doesn't fix the backs of iPhone because the glass is fused to the phone If you didn't purchase AppleCare+ when you bought the phone you can buy an Out of Warranty replacement for $449. If you bought AppleCare+ when you bought the phone the cost (assuming there is no other damage on or in the phone) would be $29. AppleCare+ can be a very smart investment for these expensive and breakable devices.

See this link --> iPhone Repair - Official Apple Support

No, they don't. A case is a wise investment in protecting your phone from scratches and dings. But a case cannot prevent glass breakage in all situations. As such, no case sold by any company, Apple included will repair or replace a phone if the phone is damaged in a fall.