Zipcar Charging for a service not used ny, New York

I PLANNED MY NEW YEARS VACATIONS AND CONTACTED ZIPCAR TO RENT A VAN I REQUESTED A VAN FOR 10 PASSENGERS, ALL OF THEM WITH SEATBELT, THEY OFFERED TO ME A VAN FOR 7 PASSANGER ONLY AND SAID I CAN TAKE ALL 10. THE TIME BEFORE MY TRIP I CALLED THEM AGAIN AND ASKED IF THEY HAVE FOUND THE VAN HOW I REQUESTED THEY SAID THEY HAD 2 VANS A TOYOTA AND A HONDA BUT ONLY FOR 7 PEOPLE SO I TOLD THEM TO FORGET IT, THAT I DO NO WANT ANY VAN THEN. SO NOW THAY ARE CHARGING ME FOR $721.66 AND SENT ME INTO A COLLECTION AGENCY, I WENT TO THEIR FACILITIES HERE IN N.Y. AND THEY TOLD ME THEY COULD NOT DO NOTHING BECAUSE ALL THEIR BUSSINESS ARE VIA INTERNET, SO THAY START ALSO TO SAY I JUST HAVE TO PAY THEM 360.83, I DID MY COMPLAINT WITH CONSUMERS AFFAIRS AND EXPLAINED ALL THE SITUATION, ZIPCAR  DO NOT KNOW HOW TO DO BUSSINESS. THEY CREATED A MESS WITH MY CREDIT AND THEIR COLLECTION COMPANY IS STILL CHARGING ME WITH $721.66 AND RECEIVING ALL THAT STUPED MAIL THEY USED TO SENT TO SAY THEY ARE TRYING TO COMMUNICATE WITH YOU.