Product pictures copyrights

Hi everyone! I am new here and just started to sell my works online. Right now I’m working on a magazine template. I want to create demo of my product. I’ve seen that many of you use for your previews product pictures from online shops, like for example Bershka, ASOS etc. I read their “Terms & Conditions” about intellectual property and they always write that this is not allowed to use their content in any way. So I decided to write emails with request for using some of their images for the preview and give credit to the shop in the description. Unfortunately, it was 2 weeks ago and I still didn’t get any response. Did you have similar experiences? How do you get your pictures? I’ve seen there are no any product images like that on websites with free stock photos (I mean with a product only, on a white background). Will be greatful for your help.!