Scamming customers from popular and well-known shops

SL Geek posted a video discussing getting a used and possibly fake product from "infinitystore.lk" which was said to be brand new and unopened. As he said, if a well-known tech reviewer gets scammed from a popular shop, the chances of us getting scammed are huge.

Currently, I'm looking forward to buying a mobile phone. Are there any particular shops that I should avoid? Do you guys have any similar experiences?