You may need to escalate your case with Netflix. The support person at Netflix may have misinformed you. Netflix is indeed accepting payment from Apple on existing accounts. If you’re a new subscriber or returning subscriber you are not given the option to start or restart a subscription through Apple.
>>Pay for Netflix through Apple
Apple billing for Netflix is not available to new or rejoining Netflix customers.
If you are trying to sign up on your Apple mobile device, you can go to Netflix.com on a mobile browser and use a different payment method.<<
>>Check if Netflix is billed through Apple
Check the Membership and Billing section of your Netflix Account to see if you are billed through Apple.
If you have any Apple billing questions, visit Apple support.<<
https://help.netflix.com/en/node/25097