The Apple One subscription does not include an ad-free Peacock subscription at all. It includes Apple TV+, Apple Music, Apple Arcade, and additional iCloud storage. With that said there is a bundle subscription for Peacock for anyone that has Apple TV+/Apple One and there are 2 choices to get Peacock Premium (with ads) and Peacock Premium+ (without ads) at a reduced rate. You can cancel that bundle that you apparently signed up for that includes Peacock and return to the standard Apple One subscription where there are no ads using the Apple TV+ programming.
If you don't have a need for the other services included with Apple One, then you may be better off with just the Apple TV+ subscription that will save you money.
You can still bundle the Apple TV+ subscription and Peacock with either the Peacock plan that includes ads for $14.99 or the Apple TV+ subscription and the Peacock plan without ads for $19.99. That compares to the standalone subscription of Apple TV+ without Peacock for $12.99.