Why is it my one year free subscription for Apple TV is not activating?

I currently have a subscription to Apple TV which expires in July. I bought a new iPhone the other day which comes with a one year subscription for Apple TV. I click on the link provided in the email and nothing seems to happen. When I am finished the page refreshes right back to the starting point. I should still be able to get a free one year subscription even if I have a current Apple TV subscription right? Do I have to wait until my current subscription expires?