I left my kindle in the vehicle

Dear Avis rentals, I returned a car at OR tambo yesterday at about 16:00. I realised at the counter that i left my kindle in the door or the passenger side. I went back to the drop off and the car had been sent back to despatch. I needed to leave to get my flight. I left my info with pamela, who was knocking off at 5 and would get a supervisor to contact me with a ref number, no contact has been made. I called your callcenter now, spoke to Natasha, she gave me lost and founds number. The phone just rings. I phoned again, a gentle man told me to call ***, it goes to voicemail. My booking number is ***9ZA3 ive now spent 20 minutes standing at your counter and made about 6 phone calls, with no joy or answer or reference number! I need my kindle please!