unable to creat a username

after creating a mojang account and verifying my email as well as purchesing minecraft, i am unable to make a user name to play online with my friends. i have not recived a email from mojang before asking me to make one, no green box on there site askes me to make one and every time i try to make a minecraft account, i am re directed to mojangs site. it has been a week since i have made the account and i still reciveded nothing. As a paying cutomer, i would like some awnsers as to why i am not able to use all of my product.