Identity theft at Hi-Fi Corporation Centurion Mall

I went into Hi-Fi Corporation Centurion Mall to collect a new phone as per insurance instructions. Upon my arrival, they made a copy of my ID, gave me a new phone and I left. Lo and behold, on the 9th March 2022, I get a notification from my bank that someone has app**** for an MTN cellphone contract using my details. When I enquired with MTN I was told that this person indicated that they work at Hi-Fi Corporation. Clearly, our confidential information is not safe with you guys, I will never purchase at Hi-Fi Corp again. Now I must run around blocking my stuff because of you. I'm so annoyed.