Need help with money

26 of August 2018 i was driving to johannesburg i stopped by montrose to fill my petrol and i poured 340 and my petrol gadge ddnt go up as usual i asked them they all laughed telling me clio renault are all like that its not only me i asked them why all this while it was going up after pouring only today i ddnt that means they ddnt pour my petrol of 340 i called and it went to debonairs and i gave them the message no one has called me back all i want is my money back.They ***** if you know what is good for you do not go there to pour petrol because they *****.i was assisted by Ellias and a manager came i gave him my details but no one has called me.