bad customer service

I bought a Powerbank at Cape Union at Baywest store, Eastern Cape PE, I not even sure when if it was 2017 or 2018. It was Faulty and unable to charge then I took it back with the slip apparently the slip was a light copy and the sales assistant asked me if I can give the original as the copy will not come clear out, the Assistant was Riyaad at that time and every time he would told me that he will call me once it is ready. I live 40km from Baywest so don't go there often but when I get there I always pop in the store then I will forever get the feedback we are waiting for it to be repaired, months went on, still no feedback then I followed up basically every month and the same story is given to me. eventually I had enough and said I want to speak to the manage at the store then it was no the manager is off sick or away. later I had to find out that Riyaad does not work there anymore, but the other assistant Naadira was aware about the story and was there on few occasions when I was there, what do I do know no leg to stand on as Riyaad took my slip, Naadira denied that me and that she doesn't know anything about it, she then gave me Riyaad number which I contact him and have sms and screenshots about our conversations regarding the power bank that I never received or replaced. Naadirah then avoided me as much as possible, I then called the store everytime when I call the store is speak to some one else, and need to explain the same story which irritates me, to crown everything off there is no trace that Riyaad did send the powerbank in to get replace and all of a sudden they cannot get the book that it was booked in, what do I do know I am known now as the ****. I eventually called the store again like 3 weeks ago i eventually spoke to a Store manager by the name of Delmay, i explained to her the story and she told me she will have to speak to her manager, following up also numerous times i eventually received feedback saying that i will have to take another power bank but the price changed and must pay the difference in. I am not happy with fighting like this unnecessary for and item that i bought and now i must pay the difference. secondly i called the store today Delmay told me that i can get a gift card, but yet again she cannot confirm the amount and that she will call me back in an hour, its been hours and still no call has been received and i know this is to be expected from this store and they do not give a Krap about their customers. Very irritated about this store, this store will never ever see me again