Switch controller owner

I need to switch owners on a device. Our customers are the original owners, but their previous landscapers were the ones with the user and password to access the account. They have now “lost it”. And it wont let us create another. It obviously says its already in use. Can you please help us.
Marina.

@7PondviewLane

Please private message me a photo of the serial number. Thanks.

:cheers: