Overcharged my by R7000

Upon traveling to south Africa I booked a budget rental car for a few days and prepaid it with my credit card.<br> as we always do I asked for all the insurance, and unlimited mileage. two weeks later AVIS deducts almost R10 000 of my account saying I used to many km/s the windscreen was cracked, ext.<br> this is totally unacceptable.