can’t delete old customers

How can I delete inactive customers? When I look in my Users section I had about 13000 customers. In the woocommerce/customers section it says about 24,000 customers. I checked the box in settings/accounts and privacy to not retain any in active customers over 14 months. Now in users I have around 9000 customers listed but in woocommerce/customers it still says the same number (approx 24,000)? Why are these not synced and how can I manage them best?