Adaptive Equipment problems of the 2006 Nissan Murano

I am having problems with the drivers side sun visor in my Nissan Murano. It will just drop down suddenly. At first I was able to pull the visor down and move it forward to help protect my eyes from the sun. But that didn't last long since it will just fall straight down and block my view. When it falls I can not see the cars in front of me. I am not a tall person but I would have to be extremely small to see under the visor when it falls in straight down position. The other day, I was driving on the freeway and my sun visor suddenly dropped straight down . It really startled me cause I lost visibility. I screamed cause I could not see the cars in front of me like I mentioned earlier. As quickly as I could I lifted the visor and held it in place and continued by journey. It was pretty nerve wracking. I could have gotten into an accident and injured my passengers, myself and other drivers. And with traveling at high speed it's was an extremely dangerous situation. My dealer said the cost to repair would be around $500. I feel Nissan should take responsibility for this and issue a recall but I haven't seen any yet. This sun visor issue is very dangerous to all of us out there on the road drivers and passengers. I hope something can be done about this. Thank you for listening.