Nonchalant DHL USA failed in informing and until I...

Nonchalant DHL USA failed in informing and until I called DHL Singapore, then realized my package was rejected at the US customs due to lack of details of the items in the package. DHL had not advised beforehand. How could DHL be so inexperienced and negligent?!!! Even refund was sloppy, took more than three weeks than what was communicated.