Ackermans review: School shoes

Good day
Yesterday I was at ackermans buying school shoes for my niece, and I am a guy, I am not used to shopping for shoes unless they are mine. As I enter the shop I had to roam around the shop to find what I was looking for but they have sales people walking around, aren't they supposed to be assisting me with what I am looking for? As I was looking for the shoes, I happen to find them and on their shoe hangers they normally write shoe sizes like the number "6" or "7" so obviously I would think its a size 6 or size 7 as I pay at the till the cashier didn't bother to ask if I had the right items since she can see that I am new to this, I bought the wrong size thinking that the shoe size is written on the hanger is the definite shoe size, only to find out that on the inside its a size 13, I feel like I was mislead to buy something wrong just so they could make a sale knowing very well that it is hard to return items during the pandemic. How do we solve this false advertising because I don't think I am the only guy who was sent to buy shoes and came back home with the wrong size because the only visible number was the one on the hanger.