Web App (Windows): Unable to delete orphaned App Service plan — Deletion fails with HTTP 409

Problem description

I am trying to delete an App Service plan named 'SouthCentralUSPlan' in the resource group 'fulfillment'. However, the deletion attempt results in an HTTP 409 error, indicating a conflict. The plan still shows a Function App named 'gap-fulfillment' attached, even though direct lookups for that app return a 'ResourceNotFound' error. I have exhausted all possible methods to delete the resource, and I believe Microsoft support needs to delete it in the backend as it no longer exists.

Environment

Azure Web App (Windows) in the region not specified in the case information.

What I've already tried

I reviewed the available case details and diagnostic information. I have attempted to delete the App Service plan through the Azure portal and Azure CLI, but the deletion fails with an HTTP 409 conflict. I also confirmed that the associated Function App 'gap-fulfillment' no longer exists when directly looked up, indicating a possible stale state or backend inconsistency.

Current status

I am seeking assistance to have Microsoft support delete the orphaned App Service plan from the backend, as all standard deletion methods have been unsuccessful and the resource appears to be in a conflicted state.