Insurance Claims Handlers

[himan]

Does anyone know if it is possible to find out who handles the claims for the various insurance companies, specifically in the UK? Reason I ask is due to the fact we had to cancel a cruise a few months ago due to my wife suffering from a medical condition and were insured with a reputable company. To cut a long story short we submitted all documents as requested to the claims handlers and they have been extremely unprofessional and have just rejected the claim due to it being a pre-existing medical condition that I hadn't declared in their opinion. However we gave them a diagnosis from the doctor and updated the insurance company day before travel and cancelled the day we were meant to travel to join the ship. The eventual diagnosis of the problem which turned out to be the condition my wife was suffering from only came over a month after we should have been on the cruise! So I do not want to take insurance with a company that uses this claims handling company as they get extremely bad reviews on the internet. We have a cruise booked for this year and need to get insurance so grateful for any advice. Thanks in advance.