If you’ve missed the opt-out window, you can still stop contributing to your Penfold pension. You’ll need to get in touch with your employer to arrange this.
When you stop making contributions to your Penfold pension, any money you’ve already added to your pot will stay there - because the opt-out window has passed, we won’t be able to refund any contributions you’ve already made.
If you wish, you can keep the Penfold pension pot as is until retirement, or transfer it out to another provider of your choice.