I have a mac and when trying to install photoshop CS6 onto my mac when I enter the serial number it is giving me the message my serial number is invalid. I have checked my account and the products are registered and the serial number is correct. the

I have a mac and I'm trying to install photoshop CS6. When I get to the part where it asks for a serial number I get the message that my serial number is invalid.  I have checked my account and the serial numbers are correct and they are registered to me in my products.  Can anyone help.  The chat line won't help nor will the phone line.