Durmail
Parcel on route to incorrect Country

Hello
My tracking no for this parcel CN009039131ZA which is addressed to the United Kingdom is now as i believe in transit to the USA??
The address on the parcel is correct and should be arriving in the UK but after a few enquiries and calls i have been told it's on route to the USA. The reason from customer services is that the parcel was scanned into the incorrect destination bag/box. How is it possible that this can happen when it clearly states United Kingdom??