Last name in Id mismatch

Hello.

If you contact Pearson VUE's customer support and are told that a refund is not possible, then I assume that you cannot receive a refund.
You can take the AWS exam as long as 14 days have passed since your previous exam.
https://aws.amazon.com/certification/faqs/?nc1=h_ls

If you fail an exam, you must wait 14 days before you are eligible to retake the exam. There is no limit on exam attempts. However, you must pay the full registration fee for each exam attempt. Once you have passed an exam, you will not be able to retake the same exam for two years. If the exam has been updated with a new exam guide and exam series code, you will be eligible to take the new exam version.

Note that beta exam test takers can take the beta version only once, after which they will need to wait to retake the exam when the official certification exam becomes generally available.

Please submit a ticket to the AWS Training & Certification customer support team, and they will provide assistance. If you already submitted a case, please allow at least 48 hrs to get a response.