incorrect invoice, no feedback after call & email

I have rented a Peugeot 107 car at Avis branch at airport of P.E on the 1st of May of ***. <br> the car was returned on 4st of May. total kilo is 747 kilometers, but I have told the branch I want to rent the car for 4 days, just returned earlier. but anyway they charged me 3 day of 141.42 Rand per day, and extra 147 killometers of 291.06 Rand (1.98Rand/liko*147kilo). which is not right, and the most unacceptable thing is they charged me 35 litres Petrol of 12.48 ZAR at 436.8 Rand.on the truth is I pull full tank petrol when I returned the car. this is totally wrong. I have been wirting to Avis since 8th of May after I received the Invoice, and get feedback from Vivian Sibanyoni and Thuto Dominic Mathathe. and I called three times and recorded the last operator's name is Thuli. I think i will never get the call from Avis about this issue, this is really disappointing. AVIS is a famous brand of car rental in South Africa, but if the service quality is like this. this is really a nightmare.