In 2010, a rental car company in XXXX charged my credit card for a deposit against damages at XXXX rate of exchange and then debited my credit card at a different rate pocketing the difference. I attempted to resolve this with the merchant but to no avail ; when I disputed this with the credit card I was stonewalled, my written letters were ignored, and after repeated attempts to discuss with them ( XXXX XXXX ), I closed the account having paid all that was owed except for the disputed amount. I now find that despite my otherwise excellent credit rating, my FICO score is being dragged down and inexplicably affecting my insurance premiums. 
At the insistence of the credit card company, all dispute processing was done on line, therefore little supporting evidence is available. However, I am attaching the final letter that I wrote them concerning the matter. 
