Horrible Customer service over faulty item

I purchased a phone at this branch the lady who I purchased from was setting up the phone and struggled to get the device working, after some time she tried to get a hold of a supervisor to sort out the problem, she was unable to do so.After an hour of waiting a supervisor came, Monique, I was told by here that they would exchange the device at this point I was already fed up and told them that I wanted a refund and I would go elsewhere,I was then told i could not have a cash refund,despite the fact that I never even held the device, and was offered a store voucher, after a while of fighting another manager arrived,Japie , but he did nothing. Half an hour later they eventually agreed to give me my money back.This is completely unacceptable, horrible customer service all round and then they still attempt to hold on to my money when then had no right to it.