Billed for no petrol

On Saturday the 31st Jan I went to this filling station to pour R50 petrol, when I got there my car was reading 22kms DTE and I checked again before paying, it still read 22KMs DTE...when I went to the management, he showed me the footage and all but couldn't show me the report of when last he serviced his pumps. I was forced to pay for no nothing. R50 rand might sound petty but the pain of giving someone your hard earned cash with nothing in return is too deep. I would really like you to investigate this because someone out there might be suffering in silence...