Bad customer service

Good day To whom it may concern. I am utterly disgusted regards to the poor customer service I have received from the manager at the cape gate branch .on the 27th earlier on the day I purchased a cell phone at the store by a very friendly lady assisted me in a very polite manner.she then explained to me if anything is wrong I can bring it back .later the day upon my return I spoke to one of the cashiers she told me that they do not return cell phones,then I told her to call her manager wanting to know why I couldnt return the cell phone with original packaging and it hasn't been used as of yet.upon arrival the manager came spoke to her trying to explain my situation as to why I dont need to the cell phone without even finishing my conversation she literally raised her voice and blantly said they do not do refunds I should phone customer service and that they do not do refunds on cell phones.then I followed her to the back of the store after she just walked away which I found very disrespectful then in front of her staff she felt da need to be rude and I told her not to shout at me i told her at the back of the slip it states that I can return an item the only thing I can see on the slip is they do not refund airtime nowhere on the slip it states that the store cannot refund the cellphone.my argument is if the phone had technical issues or beyond repairs or if the customer refuse an exchange or if they out of stock what would of happen then?