Arm rest damage

I took my car in for mechanical attention. Upon conclusion of work,my car was left in the extreme heat outside with the glass roof not covered.The whole day the car parked there with glass heat reflection damaging my car armrest.I reported that few days later when I took the car back for something and told Mercedes will respond in two weeks.When I go for initial service I was told Mercedes refuses to replace my cracked armrest.I am disappointed with Bedford view