Almost everyone who has flown much has a story (or more than one) about lost or damaged luggage, and holiday insurance claims regarding these are commonplace.
A Finnish man who took a holiday to Malaga found that some items went missing from his luggage on the return trip and he proceeded to make a claim against his insurance policy. He had used Finnair's website to see what to do and concluded that he could telephone their customer helpline to report the matter.
Finnair refused to settle with the insurer because the regulations in the Montreal Convention (which covers airline traffic) stipulate that such losses must be reported in writing within seven days of the receipt of the luggage. There was no doubt that the airline had a written record of the claim, but as notification of the loss was not made in writing, it declined to settle.
The legal argument that ensued went all the way to the Court of Justice of the European Union, which ruled that the claim was valid because a representative of Finnair had made a record of it. The Court also ruled that the use of an electronic system (such as a website complaints page) would count as a formal written complaint.
However, given that the decision turned on there being a written record of the claim, it would be risky to rely on a verbal complaint only as it is important to make sure that a written record is held by the carrier within the seven-day time limit.