Why do i have insurance??!!

So I app**** for a claim for a laptop. It was denied due to it being in a car. I fully understand the point made behind the declining of my claim, due to it being in the car it was not listed under “portable items”. Here is my issue with this - I have never in my life when taking out insurance been asked to list items under the “portable items list”, except for cell phone as you sometimes get asked if you would like to insure a cell phone, but never anything else and never referred to as this, they just aske if you would like to insure a cell phone. When I contacted Discovery the first time for insurance I asked if I must send a list of items with photos I owned through and I was told no it is not needed, thus it would never be listed on the so called “portable items” list and no one even told me this must be done! Now I am being held accountable! Then further a laptop is classified as a home computer that is by definition a portable home computer, this is an item that stays in the house unless for some reason you need to take it with you then you can. Majority of household have at least one now days, how can such an item not be covered?! I have full grip and understanding of things like cell phones and such. But really. Why do I even have insurance then? This has cost me R18000.00!!! Not to mention all my payments to Discovery for household insurance! Feels like insurances deliberately do this to get out of paying out claims...