A petrol attendant with a very bad attitude

After waiting for about 10-15 minutes in the queue for petrol, Hans the guy serving in my line walked away from my car and proceeded to serve a car that had come after me in a different line. I then called him and asked told him I had been first and could he serve me. He proceeded to show me to wait using his hand and after telling him I wanted to speak with his manager he told me not to talk to him and proceeded to assist another car. He then denied all knowledge(still with an attitude) of this and denied to be the person responsible.