Hi Ashley,
Thank you for contacting the Microsoft Community.
I understand that you're having an issue rescheduling your exam, and I can sense how significant it is for you to reschedule your certification as soon as possible. Allow me to further assist you in regard with this.
Since you mentioned that you're using the same email address that you used in scheduling your exam but still encountering an issue, for me to further investigate, kindly try to follow the steps below while performing a step-by-step screenshot using Problem Steps Recorder (PSR) (click this link for MAC device) starting from the sign-in page up until the last page that shows you're unable to proceed.
Log into your Learn profile using your personal account.
Select Certifications in the profile menu.
Scroll to the exam appointment you wish to reschedule.
Follow the on-screen instructions. For reference, you can visit Exam reschedule and cancellation policy | Microsoft Learn
Please send the step-by-step screenshot in the private message I initiated, along with the requested information to locate and verify your account.
Meanwhile, you can also contact the Pearson VUE Support team for urgent assistance in rescheduling your exam, as they have access and proper tool to modify your exams. Kindly refer to their contact details below:
Pearson Vue: https://home.pearsonvue.com/microsoft/contact
I look forward to your response. Please note that if no response is received after two business days, the case will be closed and locked. After the case is locked, we will no longer be able to respond, even through Private Messages. Thank you.
Best regards,