Sixt staff was unfriendly and unhelpful

I booked a 5-day rental between 23.12.2022 and 28.12.2022 on Yolcu360.com. When I picked up the car at Sixt Antalya Airport, I told a short, thin woman I could extend it for one day. If you tell us on WhatsApp one day before your girlfriend's lease ends, we'll extend it with no problem. This verbal statement prompted my 5-day rental transaction. Surgery in Ankara requires me to drive from Antalya. My doctor postponed the 26.12.2022 surgery to 27.12.2022. Due to the delay, I contacted Sixt via WhatsApp on 27.12.2022 and was told they could not extend the rental period and I had to return the car. On 28.12.2022, I risked my health and left Ankara for Antalya. 28.12.2022 at 16:30, I delivered it to Antalya Sixt. During delivery, I told the manager he risked my health and didn't grant the extension. I said your actions were bad and caused me pain. This person has a very wise attitude, he said we don't have to extend the time since you had a situation if you rented for 6 days instead of 5 days. Sad that such people are Sixts. A friend said I smoke in the car, which is prohibited, so I didn't smoke. You rent smoky cars. I said the vehicle's pollution is from normal use, delivered it, signed the document, and left Antalya Sixt. An hour later, an Antalya Sixt official messaged me on WhatsApp and asked to withdraw 400 TL from my card as a vehicle cleaning fee. I said I'm not responsible for cleaning the car, I've rented from Sixt dozens of times, and I've never paid a cleaning fee and haven't accepted it.