Price change when convenient for them

I went to archive in springs mall to buy an adidas shoe. The price on the shoe was 599.99 and when I was buying it they went to the back and when they came back they wrote a 1 in blue pen which now made it 1599.99 rand. I find this very unprofessional and makes me doubt and not even trust the brand. This happened today 7th of September 2023.