poor service tempest car hire

I hired a car from tempest car hire.I filled the car up at the airport and mentioned this to the staff,but i was still charged for refueling and more petrol .I spoke to Bernadette Papier ********** and have sent her 6 e mails since the 11 10 2018 without a response even though she said she would sort it out and come back to me. rgds john