Customer service?

My client went to collect and her locker was empty. I contacted customer service and after 2 days they stated that the parcel was placed in the locker.

My client contacted me yesterday stating that someone phones her because they found her parcel in their locker.

So what parcel was placed? Customer service does not read what your actual problem is and they do not give replies related to your issue.

This is the first time I've had this issue, but the customer service was horrible. I can't imagine what would happen if the problem was worse