Worst customer experience

I recently had a vehicle accident and I registered my claim with my insurer Std Bank Insurance however I have not been happy with the service I received from them. They have written the vehicle off based on their assessment and as their client I have requested that I take the car in for a second opinion but it seems like they are refusing. I am the vehicle owner and should be given an opportunity to register my dissatisfaction with this company however they are doing things as they please. Yesterday as I was enquirying about the assessment they then decided to move the vehicle from their yard to an auction house without informing me. Before the vehicle is sold off I would appreciate it if you could give me an opportunity to get a second opinion from an authorized BMW repairer, if as a customer you refuse me this then I will have to escalate the to the ombuds.