Hi @user00854,
You should contact your certification center either https://www.examity.com/ or https://home.psiexams.com depending which one you have choose for your exam - you will find contact form on both above sites. They will provide answer to your question.
Before the exam, you should also receive certification center exam policies that includes information about exam reschedule, and steps in case of any issue during the exam itself - this also could be useful to get an idea what you can expect.
I do not think Adobe will provide you a new voucher because this is certification center and person who is taking the exam responsibility to take care that exam will happen without any issue.
Of course you can still try to contact Adobe as well via certif@adobe.com - this is a dedicated email address for any Adobe certification questions.