Worst customer service ever

I am disappointed and very unhappy, I would like to report an incident that happened today 31 October 2019, I walked into PEP cell 4836 at Maponya Mall the cashier by the name Nelisiwe was rude and she refuses to listen the customers she will not hear you out and imposes her opinion on her customers i.e me to that expend she taps the counter and says "listen". Firstly the lady that assisted me on on the 8 October 2019 didn't inform me that the 7 days warranty is inclusive of the activation date of the cellphone, there I was on the 15th thinking that I my cell phone is still under the 7 days they also confirmed that it is still within the 7 days. I explained to Nelisiwe that the phone is slow and the battery doesn't last, the phone needs a software update everyday even after updating it she tells me "it's normal for Nokia to always need to be updated that is how this device was designed" she then compares her Sumung phone saying that she had to move or delete things from her phone for space and it was normal so I too had to keep updating the software I wonder if she is a technician. She then stresses that there is nothing wrong with the phone and then finally says that there is a Nokia rep that will check the phone before she can book it to prove or validate what I just told her we waited for an hour to 2 hrs and she called the guy he said he was in meeting she then told me to leave my phone with the slip and my contact details and when the guy comes they will call me, and said to me the phone is still within 7 days it's okay. I left she called me later that day around past 5 to inform me that the guy from Nokia didn't come because he was stuck in a meeting the whole day. The next day I went to pep cell to try and get something that will prove that they have my device and then the guy from Nokia came I then told him what happened and he checked the phone and confirmed everything and spoke to Nelisiwe telling her everything that I told her and what he also noticed. She then tired to refund me as I as also expecting but the system declined and said that the phone was no longer under the 7 days I didn't even fight or argue. She then told me that they now have to book the phone for repairs and it would take 6-8 weeks before I get it back still didn't fuss or argue about it since they made a mistake. Yesterday 30 October 2019 she called me informing me that the device is back from repairs and then this morning I went there to fetch it only to find an old phone with finger prints and stains. I then said to her the phone is old she tells me the phone is new and it was replaced with another one since the IMEI number is different she checked it already I told her that I didn't want the phone and she said it's my query I should call Vodacom Repairs they are in Vanderbijlpark and tell them that I don't want the phone she did what she was supposed to do which is book it in for repairs. I then kindly asked her if she could call in for me she didn't even wait for me to finish my sentence that's when she taped the table and said " listen" I should call vodacom repairs they are in Vanderbijlpark and tell them that I don't want the phone she even pointed out me the number on the repairs paper. I took the phone and said thank you since I couldn't even get through to her i didn't want to waste my time even further since I was on my way to school. I paid for that phone and I was taken for a ride as a customer I would either like to be refunded or get a new phone. Because I even explained to her that I needed the phone to do my school work and I even loaded my school applications on it to help me study and also please deal with Nelisiwe from pep cell Maponya mall. You would agree with me that the way they handled the matter is not the way you handle your customers. But now I understand that it is no longer a mistake but they take advantage of their customers. And the cashier makes you feel stupid with her sarcasm.

Please assist