Facing error Duplicate add-on ID found

We are distributor of Firefox extension for dragon professional.

It’s ID is dgnria_pro.firefox@nuance.com

Now we have done some modification to the same extension, while publishing it shows error as “Duplicate add-on ID found.”

Earlier we have used same ID for the Firefox extension in the year 2018.

Currently we have opened new account with same ID “dgnria_pro.firefox@nuance.com” and faced the mentioned issue.

We are expected to publish our extension with the same extension id as we don’t want our existing customers get affected.

Is there any way with which extension id “dgnria_pro.firefox@nuance.com” can be deleted from backend , so that we can reuse it.