Shell garage not ayoba.

Since its lockdown and we are only alowed to buy essential goods at specific stores. Today this situation came as a challenge to me the oil price keeps on dropping and its affecting the price of petrol ect. How ever call it ignorance from my side, why I'm I paying R41 for a 500ml of oil engine , we're as engine oil at Game store is selling for R33 at 5 litters. I'm really lost now.