I am a foreign trade salesman. At the end of last year, I received a foreign trade order, which was produced by the factory I found myself, regardless of the company. This year, the goods were delivered. first of all, to find out who inspected the goods at last, there should be an inspection list. If it is the QC of your company, then you should take the inspection list (with the signature of QC) and find the relevant person in charge of your company. It is the QC inspection and release of the company that proves that there is no problem with the quality.

Secondly, your inspection report should have been sent to the guests. Why didn't they raise any objection at the beginning? You find that email and ask them back.

again: did you sign a processing contract with the factory? If so, it should indicate the quality requirements. If not, the general factory will not pay attention to the quality problems after delivery. But you can also communicate with the factory, such as promising to cooperate with them again in the future ~~

I hope it will help you.