Bad customer service

I went to Edgars yesterday to purchase with a cellphone voucher, and the cashier told me that it was her first time reedeming a cellphone voucher and that she wasn't sure how to do it, so she called her supervisor Ronel, who came only to stand and chat with one of the staff members on the floor while I waited. The cashier called her again and she said was that I can wait, I waited there for more than 20 minutes when eventually another lady who is also a supervisor and happened to have just luckily been passing by helped. I lost a hair appointment due to this, and to be honestly I am angry and disappointed with Ronel's lack of professionalsm. <br> The cashier's name is Portiah Bester and she really tried her best to stay professional under such circumstances.