Not to Clients Satisfaction

I am totally appalled by the decision of the Vehicle Assessor with Standard Bank Insurance. I met an accident on the 25 March 2015 and on the 7 April 2015 the repair was authorized BUT, when I went to the Panel Beaters were my car is, I was told that 3 parts(Front Bumper, Fender and Fender lining) was going be alternate parts, and I am not happy with that because MY CAR HAS ALL ORIGINAL PARTS, and by them using alternate parts is going to depreciate the value of my car. My car is insured for R69950, the quote with all original parts were around R20000, but the Assessor authorized the for R16980 thereby using the alternate parts. but with the ORIGINAL PARTS its below 30% of the Cars insured value. Then I was told by the consultant that if I want original parts I must pay the balance for it, plus I still have to pay the excess which I know I have to do. yet I am the client, and that's the reason I took insurance, incase of an accident my car will be back to original like how it was. I have been a client with Standard Bank for 20 years, and this is the service I get, its very disappointing. Please can someone assist me with this matter.