according to the contract law, it is required to bear the liability for breach of contract.

evidence you need to prepare: contract

if the contract is famous for breach of contract, you can get compensation for breach of contract as agreed. Meanwhile, you have the right to terminate the contract.

if there is no breach of contract clause in the contract, you can claim compensation according to the actual loss. Generally, it won't exceed twice what you paid.

of course, you can settle it through negotiation: reschedule the delivery date and bear the loss of breach of contract, that is, make him pay less.