Think it through. How do you actually "cryptographically hold" someone to anything? You take them to court.
Guess what you can do, right now, without the blockchain? That's right, you can take them to court.
You're just reinventing normal contract law with extra steps.
The cryptographic part doesn't even help you when you can just say in court that "here are our records that show we gave them these packages, here are our records of customers filing complaints that they never got them" and that is completely fine.