Mazda 6. Rear defense price !!

Hello:
I would like someone to help me with a problem I have had today.
Parking a car was a car was a dark silver mazda alleged metalized paint.
He rubs his car in the back defense in a corner of the right side.
I got very snowy since I have never had any altercation with the Cohe, the boy made me sign a part, I did not know how to react. The point is that when I got home I looked at my car and realized that I had no scratch simply had a kind of cement in the car that giving it a cloth.
I returned to the boy and begged him not to give part to the insurance, that I paid him the arrangement and he told me that it was better to give the part that the arrangement would cost more than € 200.
I have never done anything of sheet metal and paint in my car so prices or idea, but it seems to me that because of a rock, it has no bun or anything, it is something expensive. I don't know what you think. He says he has to paint the entire defense !!
My question is also: that kind of cementque I had in the car means that he had already had an accident before there and had fixed it?
I don't understand why nothing happened to me and his yes.
What price would I have if there were no all defense to paint?
Paint all the defense about which prices would oscillate?

Many gacias.

Hello, I do not know how you are, but here in Chile, insurance only covers accidents on a established price not for small things, you want the guy, you are making you pay all the bumper so that the insurance pays it, the cement layer is the lacquer of the original paint of the mas. And the patch is not noticed, your car does not happen to it because the mazdas defenses are carvone fiber and yours is of a harder material is like grateful a glass with a diamond, usually the complete cloth is painted, that is, the piece not only the rallon that does not do it no one and less in a mazda, the value of painting a defense of those aca in Chile is around 45,000 thousand pesos. Transform that amount and get an idea. But as I tell you, how much is the value in your country. If I can help you in a way or something else, do not hesitate to ask greetings and abrasses.

Graias !!
I am Spanish, rather Galician !!
I will have to look at how many euros. Anyway I suppose prices are different.
How long would it take time to repair it? So more or less I would get an idea.
I suppose that if it is more than € 200, it will be better to give part to the insurance even though it goes up the following year.

Thank you so much.

I will never upload you as much as what you are going to pay, here in Chile two days are delayed as a maximum if the weather is very cold and what they take to prepare the paint, if you have doubts about your car or something just as Galic