Europcar- Poor ettiquette and unauthorised fuel top up on a full tank returned vehicle

I was given a hired car by my Insurance and which was delivered to me.I returned the hired car,Kia Rio on the 11 May 2019 around 10h00,collected by your driver.I had topped up the fuel to full tank ,and taken a pic of such and shown to your driver on the same day.My partial deposit was refunded only to find out that it was credited R300 short.When I followed up with your office on the 22 May 2019 at 12h29,with Phumele she stated that this was debited for fuel.I explained to her that I returned car with a full tank and also chatted with you at 12h36 to explain same. I find this extremely unbecoming and without consent that you guys chose to do this ‘’ intentful, deliberate and rogish’’ act.I’m prepared to take this matter up further,but giving u guys an opportunity to rectify and refund the shortfall of R300 or so,for this unauthorised deduction from my credit card.*Did u guys top up over the maximum,so that u run around on our money?No proof sent to me as well.Not again will I use your company and I will network this poor service to all that I meet. To date no response to e-mail sent to the Central Durban Branch Davlan Reddy.