I got ribbed of At Engen Klein Karoo by Cashier!

Hi.<br> Good day. As a customer i always use Engen. because i was happy with their product quality and service. but until yesterday. i was on holiday in Oudtshoorn. i drove from Capetown ti Oudtshoorn with full tank with my 1.4 Hyundai Getz. when i arrived Oudtshoorn i saw my fuel tank was half. i saw Engen garage on main road and as usual and i asked to stuff full tank unleaded. he was very friendly.when i wanted to pay he said i have to pay at cashier. i parked my car and went to pay with my card.guy was keep asking me questions and i was busy answering. i wasn't sure he wanted to keep me busy or what? i forgot to asked how much was my total amount and i couldn't see also cashier never told me how much and how many litre was my fuel? because they were both keep asking me questions and busy keeping me busy.i just punched my card pin. guy even didn't wanted to give me my slip. but i was insisted and he gave me and i put in my pocket.when i arrived to my b&b room i was my slip and i said there is something wrong. i was cheated by stuff. half tank hyundai getz R530,29 cents? 40.917litres?this is impossible. please Engen as a responsible company. Investigate this ***** and refund money