Treated like a thief at Spar Rosmead

I have been supporting this Spar for many years through all of it ownership changes, I have never had a problem and most of the people know me from shopping there so frequently. On this occasion I went with my girlfriend and she paid separately at another till while I paid at another for 4 red bulls not even 2 tills away. I then walked back to my girlfriend and placed them with what we had purchased in one packet to save buying another. I was then accused of trying to take the red bulls without paying. The lady from whom I had just purchased the red bulls from had already thrown the till slip away as I did not want it. She signalled to the teller who refused to accept my purchase as valid and made her dig the till slip out of her bin. I then went to the manager to question if this is how they treat paying customers to which he replied that he doesnt know what a thief looks like and that the way in which the teller handled the situation was correct. This Spar no longer knows anything about customer service and as a result I will never support the Spar Brand ever again. They have completely lost touch with the people who live 1 street away