Hi Good Morning I am perplexed by your Post.
Have you bought something from Olivias Trains online. Have Olivia's Trains Tried to deliver to you with DHL.
If so the Online selling regulations come to mind.
If you Ordered the wrong item Then it is your fault.
If They sent the wrong item that you paid for it is there problem and are obliged by law under the distance selling regulations to put it right including postage/ Courier.
Even if you paid the postage/ Courier it is Olivia's Trains Contract. Olovia's Trains has to provide you with a Return label
Babs