The company is a scam. Their shoe sizing is based on nothing you will see here in the UK from any reputable retailer and it is clearly intentional. I ordered shoes from them in a UK Size 12 and the pair I received were not even a Size 10 (despite the packaging stating Size 12). When I requested a refund or exchange they refused and then offered me a 'special deal' where I could pay even more to get the shoes in the size I actually ordered.
It is very clearly an intentional marketing mispractice and you should avoid this company like the absolute plague.