Simplilearn — Exam voucher provided is invalid

I have been trying to reach out to Simplilearn on the invalid exam voucher provided for PMI certificate program (course has been completed).

I issued the ticket on Simplilearn’s platform on 23rd Jun, while receiving the system’s auto reply saying that they’ll get back within 10 hours, there is only dead silence (27th).

Calling, reaching out to account manager, updating the ticket - nothing works.

Is this a scam? If not, I’d expect a resolution ASAP. The ticket number is: #01829289.