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I recently started receiving emails saying I have a case that needs to be closed.  The text is below.  But I can't find anything in my online account or any direction as to how to fix this situation.  Does anyone know what to do with this?

This is a follow up to case number 15132764247 sent on 03/19/2025. As of this notification we have not received a response and this information is critical to supporting your account activity. Please respond by 04/18/2025 to avoid any adverse actions on your account.