Everyone drops their phone sometimes or puts them in their back pocket and then sits on them. It happens to everyone. Usually no harm is done, but it all depends on how much pressure is used and the force of any impact. Most regularly used phones have the kinds of knocks and cracks which can be seen on your phone and are still useable. However manufacturers are often reluctant to repair a phone for free if it shows such signs of damage. It is disingenuous of Samsung to call a scratch a “crack”. You would think they know the difference.

I am sure when you bought the phone you were offered accidental impact and water damage insurance. It is part of the business model to offer it. Most people take the insurance to cover situations like yours. Check your purchase contract to see if you have the insurance. If you refused it, it is probably also mentioned.