Zelda from Eastgate Mall at Starbucks is so rude and disrespectful

I have been nothing but pleased with both the service and staff from Starbucks at Eastgate. Sadly of late I have been rather harassed as a customer, there's a lady by the name of Zandile who always stands by the point of sale to make sure that I pay whatever it is that I am having,it is so apauling and rude to say the least. It is such a pity that such people drag everybody else down with them,a day ago I went to the store with my sisters to spoil them to some Frappuccino's and Lord was I not embarrassed in front of my sisters and other customers,Zandile made such a scene in making sure that "I pay". In all honesty I can very well afford a cup of coffee,just to be clear and the manager does help,if anything she instigates such apauling behaviour. I honestly love going there,but at this rate I don't think that it is worth me spending my money there. And all this rudeness because I have healthy relationships with some of the staff. Rediculous is not even the word.