A report to Montblanc is worthwhile, since the maker actively pursues cases of product piracy and welcomes such reports; often even the threat of this report towards the seller is enough, because a cease-and-desist letter turns out significantly more expensive than the purchase price. Contact runs via the contact form of the Montblanc website. In parallel one should absolutely use the eBay buyer protection, since purchases there are insured, and possibly involve PayPal. An own court procedure is mostly not financially worthwhile, because lawyer's fees exceed the dispute value. Before steps against the seller, securing evidence by photos, especially of the nib, is recommended.