Over charged for a booking

Very bad experience with my booking. Booked for 2 nights with my credit card, and booking.com took an extra night on my card. The communication from them is that the booking was extended by the hotel, and i called the hotel to confirm but they have no records of an extention. Their RSA number doesnt work and is always offline. Very disappointed. I actually cancelled my card to ensure no future transactions like this happen from them