Disgruntled customer

I purchased a 9piece bucket from KFC which is on special for black Friday for R99. I asked for the food to be delivered to my house the guy at the call centre was very helpful so was the delivery guy. However I was charged the full price for the chicken which is R124.90. I called the store directly to query the bill from a very rude lady who refused to tell me her name. She proceeded to tell me that the prices that I am charged when I go through the delivery service are not the same as when I'm I walk in customer. Now let's be clear I don't mind paying the full amount but don't mislead customers and tell them that something is on offer when it's not. I thought the price you see is the price you pay. And also please take your employees to customers service training. I wasn't helped the way I had hoped I would. You work with people without us there is no business. I didn't appreciate being insulted over the phone by one of yours. Nthabiseng Aphane was the cashier. Please sort it out thanx.