Budget Car Rental San Antonio Airport

I rented a Toyota Corolla online from Dallas Fort Worth Airport from Budget and requested to return the car to a different location, the San Antonio Airport This trip was for business I turned the car in on time, actually a little early on December 18, The gentleman that was there to check the car in, printed out a paper of the record of returning the car but wouldn't let me have a physical copy He told me to take a picture of it on my phone, so I did He proceeded to say that he would need to fax that paperwork in and I was good to go I filled up the car, everything was in great condition I followed all of the rules Fast forward to today and I have dealt with issues for WEEKS - they are saying I never turned the car in They have posted over $of EXTRA charges onto my credit card, on top of what the car actually costI am receiving phone calls EVERY DAY saying I have not turned the car in I HAVE RETURNED THE CAR! I have now called billing, customer service