Overpriced and 52%mark up on parts

I took my car in because I had issues with my wiper. They had to book in the car. Micheal and other lady insisted that the quote is only applicable when they have to strip and if the warranty is paying it falls off. They said once the assessor comes in, then I can have the car back and bring it when the part is available. They advised that the issue is with the motor and the part they can only get from the agent and it is R10700 Labour is R550 x2 hrs.

So Thursday the assessor went in and told Micheal that I will come fetch my car and now he said that the boss said I must pay R395 because they had to strip. How much stripping was done, as they only open the front windshield and took out the motor.

I did my own research and called Renault agent and the part is R6990 with that and Bosch had a 52% mark - up and the lady said the are allowed by the warranty to add 20%but their quote has 52% added on. I told them I am taking my car somewhere else and I don't trust them anymore.

I don't even understand why they had to charge me.