CSG M519 Locked to Enterprise GoodCloud (Purchased Sealed on eBay)

Hello, I recently purchased a brand new, sealed CSG M519 router on eBay. Upon turning it on, I discovered it is hard-locked to an enterprise GoodCloud account.
I have my eBay invoice and a photo of the bottom sticker ready to verify ownership. I have sent an email to the support but there were no confirmation email received. Could a staff member please open a secure private message with me so I can share my MAC/Serial number and get this device unbound?

Thank you!

Hi,

We noticed that you have already reached out to us by email regarding this issue.
Please continue working with our support team through the ticket system so we can assist you more effectively.