Charged for an existing problem

I hired a car in Windhoek for a week. Every day I had to visit a service station to pump the front left tyre as it had a slow puncture. I reported this on my return and was asked to complete a \damage report"form which I did but explained I had not damaged the tyre but I filled out the form so the next client would not have the same inconvenience. Subsequent to my return home my credit card was debited with the cost of a new tyre (N$667) and a handling fee of N$500 plus VAT. I have sent 3 e-mails asking for this to be rectified/reversed but have not even received acknowledgement of the e-mails despite sending to the same address where they originally rep**** that I had been charged for the tyre."""