Complaint about an Imcompetent Manager

I was treated badly by the manager ,her name is Margaret at pick n pay hypermarket in Northgate shopping centre,you know this old lady gave me a horrible service,even worse it was in front of pick n pay staff members,banging a table telling me that I can escalate this matter shes doesn't care,I mean who does that?,no wonder why most of their cashiers are so rude,because of their useless leaders like Margaret,that lady is bitter and stressed out,she don't know how to speak to people.Im very disappointed of her bad attitude.