The customer infringes the patent.

First of all, there is no legal basis for the customer to say that the goods have not been sold, so the processing fee is not paid. The customer should pay you the processing fee according to the processing contract.

Secondly, creditors have liens on processing contracts and warehousing contracts. On the premise that the customer fails to pay the processing fee and storage fee as agreed, you have the right to retain the goods and get the priority of compensation for the goods.

Third, despite the lien, you can't handle the goods at a low price yourself (if you reach an agreement with the customer). If handled by itself, it may constitute infringement.

Fourth, the way to realize your rights is to keep the goods and then bring a lawsuit to the court. Your lawsuit should be supported by the court, and then the goods should be auctioned and sold under the organization of the court. The proceeds from handling the goods will first be used to pay the processing fees and storage fees owed to you by customers.

Article 234 of the Property Law stipulates that the lien holder has the obligation to properly keep the retained property; If the retained property is damaged or lost due to improper storage, it shall be liable for compensation.

Lien, as a legal security interest, refers to the creditor's possession of the debtor's property according to the contract. When the debtor fails to perform the debt within the time limit, he has the right to retain the property and get priority compensation for the property. It is only applicable to creditor's rights arising from custody contracts, transportation contracts, processing contracts and intermediary contracts. Its acquisition must satisfy both positive and negative factors. The positive elements are: the creditor must legally possess the debtor's movable property; The creditor's rights have expired; The occurrence of creditor's rights is related to movable property, and "relationship" means that the occurrence of creditor's rights and the acquisition of lien are based on the same contractual relationship or the same life relationship. The negative elements are: the possession of movable property is not obtained through infringement, but must be legal possession; The chattel lien does not violate public interests or good customs; The chattel lien shall not conflict with the creditor's obligations.

The effectiveness of lien mainly lies in the possession of the lien, the right to collect the fruits of the lien and the right to priority compensation.