Istore Eastgate pathetic service

I went to buy an iphine 11after swiping my card the transaction went through from my account and my phone alerted me. The store manager said it declined. I had to go to the bank which indicated a proof through my statement that it went through. I went back yo the store, tbe managercalled Monica refused to engage with me. She is even refusing to give me declined slip or proof. I have called istore headquarters on several occasions tand sloke to Dimakatso and to recardo to no avail. They have been promising that Monica will get back to me till mow. I went again to the store and ske said the was no wifi therefore she cant help. She was extremely called and had no customer service.