Alison Jennings

I ceased self employment in 2020 and notified HMRC at the time after submitting a final self assessment form. Since then, I worked as an NHS employee & have subsequently retired. I have just received an email asking me to submit a self assessment! I submitted a request for removal form yesterday but now realise that I put the wrong date for cessation of self employment. Had I put the correct date, it wouldn't have accepted it anyway because it's more than 4 tax years ago. I've tried online chat but no advisors are available. Help! How do I correct the error please?