Had the worst experience ever at Usave Langebaan pricing for a certain glass was R6,99 so I took 10 glasses when I got to the till it scanned R13,99

Had the worst experience ever at Usave Langebaan pricing for a certain glass was R6,99 so I took 10 glasses when I got to the till it scanned R13,99. I then asked the Manager for assistance on which he rep**** I have to finish this ask some else for assistance. I was very disappointed in the service that I received.