Cayenne did not fufill it's part of the contract

I purchased a vehicle from Cayenne in July 2014. I took up some of the extras they sell with the car, such as Cayenne car PPF Mirror which is protective coating that they add to the mirrors to protect the paint .<br> <br> When I collected the vehicle I was told that the Mirrors were not coated with the protective coating. I was told this by James Ridley, he also said that I should give them a time and address where the vehicle will be so that someone can come within 2 weeks to install this coat on the mirrors. <br> <br> They did not come, they also have not responded to my emails regarding this.<br> <br> I have been paying for this product since I collected the car. I now do not want this product and would like a full refund<br> <br>