I bought AJ4 white cement, and the seller insisted that it was normal, not a defect or a workmanship problem.

This is peeling. He said yes, not because of workmanship or defects.

But! This was accidentally made by the boss when he bought the goods himself. It is the boss's own inventory problem, or it is not packaged well in the express delivery process. Anyway, it must be the boss's responsibility. If it is Taobao, please contact directly for a refund ~