Complain about customer service

Good day I have a complaint to make about Shell Hillcrest KZN by Oxford Hillcrest. I was assisted at around 7:50 pm by a lady at the teller who was rude and irresponsive as she did not greet me back and looked at me in ugly stares. This was today on Tuesday 7 May before 8pm. I do not appreciate this service because I work in client services and know this is not how you treat your customers. We all have bad days but it is not fair to be unprofessional and unpleasant in your workplace especially towards people who are like me who also deal with clients and know that you have to be professional no matter what. I am so disappointed and I would like the owner of this garage to know and be aware of how unpleasant and discriminatory his or her staff can be. I am so upset mostly because I know that you treat clients with respect no matter what you’re going through personally. I am offended. Even though I know that this is beneath me I am still unhappy with the unprofessionalism.