Warnings of expired credit card despite billing update!

I get regular annoying pop ups from Norton saying "Oops! your credit card has expired" and warning me that my imminent renewal of subscription will fail. I've checked this twice so far and my new PayPal selection is still there in my Billing Information and there is no sign of the expired mastercard. How do I stop this annoying pop up?

Please post progress. 
Thanks

Turn off automatic renewal and remove payment information.   See if popups stop.