Negligence on who’s account

I had a dive computer that i used for scuba diving .. it was stollen out of my dive box and a very popular Jhb dive site .. i log the claim c927775 a week later they send me a assessor by the name of Roxanne Parker to do the assessment... she literally tells me that i was negligent and she will do everything she can ... well we walked out and she says she left her car key in my office i say “ its ok ill go fetch them only to find out that she had left the car unlocked and the key in the ignition... starange that we all make these mistakes and that yes she was lucky that they never took the car as we are situated in Selby Jhb .. now back to the claim regarding my dive computer .. well she made sure that the claim wasn’t paid out and that it was closed die to negligence on my behalf , because i was not watching over my dive computer ... not to metion that it took me over a year to get them to cover it... so it seems we paying them just so that they dont have to cover our losses .... but its great and fine that they can leave keys in the car and call me negligent...