Engen Petroleum selfish policy

I was amazed that the manager of Kloof Engen Garage in Rustenburg supported three clients who left their vehicles in front of the fuel pumps around 07:30am while shopping inside the convenient store. The other clients had to wait for them to come back from the shopping. When I questioned the manager, he made me to understand that it is ok for a client to go into the shop (and LEAVE the vehicles at the pump) after refuelling. Even if that was an Engen Petroleum policy, I cannot imagine leaving my vehicle and letting other people wait. If this policy is indeed existent then Engen Petroleum as a franchise encourages their clients to be inconsiderate towards others.