Disappointed

I ordered size 6,instead a size 5 was delivered, when the delivery arrived, i assumed it was the size i ordered &then proceeded to fit the shoes & realized they are too small. i then logged an exchange for a size 7 on the app. 30 minutes after doing this i checked the size on the box and the shoe thats when i realized it wasnt the size 6 i ordered but a 5. Now i am sitting here worried that the size I exchanged to is not going to fit and i am trying to get hold of them to rectify this matter but no one answers.