I Purchased the Adobe Photoshop Cs6 edition however the serial number emailed to me is not working

Hi, I was wondering why my serial key is no working for me when i put it in the slots? i have tried to do everything possible but nothing has been working out so well. i just bought the program today and i folowed every instructions it told me to do but nothig is seem to be working. the only problem i am having is the serial key to activate the extended verison isnt working. i have tried to make a new account but that didnt work at all. if you can please get back to me that would be great.