12 month free Apple TV+

I've had apple music for years, when the apple One subscription became available I signed up. I got apple tv for Christmas so I can use Fitness+, so got 12 months free apple tv+. I've just had my monthly bill through and I'm still being billed for the full subscription even though now my apple TV+ should be free. How can I fix this? Should I just cancel my apple One subscription and keep apple music and my free appleTV+?