I recommend starting by checking whether your account does still have Premier Membership or whether Premier has ended and the last day or two of membership is just regular membership.
To check, click on 'My Account' at the top of this page.
Can you see a yellow 'Manage your subscriptions' button on the lower right?
If you cannot, it means your Premier has ended.
If you can see that button, click it then, click 'Manage by Account' on the next screen.
The screen after that will state exactly what type of membership subscription you have running.