Product: Credit card or prepaid card

I am writing to you regarding a transaction dispute that Chase ( specifically Chase Sapphire Preferred ) could not resolve and dragged on for almost 6 months. Even though I provided all needed evidence to Chase that this transaction was for damage to a rental car that I did not cause, they decided ( without any evidence from the company that there was such damage ) to end the dispute in favor of the merchant. This was regarding a dispute with XXXX XXXX in XXXX for the transactions on XX/XX/XXXX for XXXX $ and on XX/XX/XXXX for XXXX . 
I rented this car in XXXX XXXX to go to a wedding. When me and my friend rented the car, we knew that due to our early morning flight, we would have to return the car back at night. The employee at the desk informed us that it should not be a problem and that we can just enter a garage and leave the keys in a special key box. That is exactly what we did a week later. 
The car has not been involved in any accident or scratches when we returned it to the garage. Chase could see it very clearly in the pictures attached. We took those pictures because we heard that some companies in XXXX scam overseas tourists with false charges, so we wanted to avoid that at any cost. Moreover, based on many reviews online the XXXX   branch of XXXX ( XXXX ) is known to swindle its customers. We were easy targets as we booked the car directly through them and not through a travel agency, and we left the country right after we left the car. I did not receive any communication that anything was wrong with the car, just two charges summing up to more than 1000 $ on my statement. 
I tried calling the company in Nice multiple times back in the summer, but they mostly didnt pick up, and when they did, they said they will check my claim and get back to me, but they never did. Thus, I had to dispute the charges with Chase. After a month, I received a letter from Chase claiming that I have scratched the car, but without any pictures showing the damage. As you can see clearly from the pictures, there are no scratches, but even if there were, 1000 $ is an obscene amount for scratches, which just proved that this is fraud. I sent back a document via the secure messaging system on Chase 's website which included the pictures of the car right after we returned it. And a month late I was told by a representative from Chase to write a clear document as to what has happened and send it by FAX. I did that, but nothing changed. After multiple calls, I was just told by the supervisor that he agrees that the company has not provided compelling evidence to any damage, but there is nothing that he can do. After so many months of the dispute, Chase refuses to take responsibility and even though they admit that the car rental company did not show any damage, they refuse to return me my money. 
I am afraid that my case shows that Chase has a very low bar for evidence as the rental car company did not provide any evidence of damage. Chase took the merchants side rather than siding with the customer. It is the credit card company 's responsibility to make sure its customer do not get overcharged or charged fraudulent charges by merchants. Please ask Chase to re-open the dispute and only charge me if the merchant provides evidence of damage inflicted by me.