AWS Billing can't post the Training & Cert Invoice (for SKillBuilder Monthly subs) on verified payment methods

If your AWS Skill Builder subscription is being canceled due to payment issues despite having verified payment methods, there are several potential causes and solutions to consider:

Possible reasons for payment failure:

• Insufficient funds in your payment method
• Payment method may have expired or been blocked
• Incorrect billing information that doesn't match your payment records
• Technical issues on AWS's end or with the payment processor

Steps to resolve this issue:

1. Update your payment information: Log into the AWS Management Console, navigate to the Billing and Cost Management Dashboard, and verify/update your payment method details.

2. Check with your bank: Even though you mentioned your bank doesn't see the attempted charges, it's worth confirming they aren't blocking AWS transactions automatically.

3. Try a different payment method: If possible, add an alternative payment method to your account.

4. Contact AWS Support directly: Since this is specifically related to AWS Skill Builder, create a support case through the AWS Training & Certification support channel at support.aws.amazon.com/#/contacts/aws-training. They can provide specific details about why your payments are failing and help resolve the issue.

Since the subscription gets canceled after multiple failed billing attempts, and you're able to initially access the content, this appears to be specifically a payment processing issue rather than an account access problem.
Sources
billing problems | AWS re:Post
Payment was unsuccessful for AWS Skill Builder | AWS re:Post
Cant change Payment method | AWS re:Post