PATHETIC SERVICE, VERY UNPROFESSIONAL

I had visited the istore in gateway and a lady directed me at the service desk for which I did stand in a queue and I waited for 10-15 minutes. I needed to get my IPhone assessed as the battery was going flat and I had trouble charging it because it was taking roughly 5 hours to charge to 50%. I spoke to an Indian lady at the service team which claims she was a technician. I explained the situation to her (btw she was not very friendly), and all she told me was to update the software and the phone will be working normal. I asked her if I can update it while I am waiting at the store,she says "no, you cannot use our wifi because it takes about 3 to 4 hours for the update to be completed". So I came back home, and I used my own wifi to update the software, and it only took me 15 minutes to update. I went back to the store yesterday and it so happened that the same lady was there so I went to her and she said that she needs to book me to see a technician, so she booked me for today at 15h00. I was patient throughout the day, and I waited to visit the store at 15h00 only to find out that she was the technician that she booked for me, which is very unprofessional because she misled me into thinking that an actual technician will attend to me today. Anyways, when I saw her today, without even assessing the phone, she claims that the battery is swelling. Firstly, she didn't even look at the phone yesterday, so how can she say that the phone looks different from how it was looking yesterday? Very unprofessional. She further stated that she cannot help me because they no longer fix iphone X, but when I went on the istore website, I saw that they are selling those phones as pre-owned, so my question is, how can the store sell these phones when they don't fix them??? What happens if I buy this phone today and tomorrow it breaks, will they turn around and tell me that they can't fix it? So my R10000 to R15000 went down the drain???it is a pity I didn't take her name. This is very unprofessional and unacceptable. As a company, you should always treat your customers fairly and not mislead them, and this is part of the fit and proper requirements. I am very unsatisfied with the way I was treated.