forest

I just received an email saying that the deadline is past, but I did my self-assessment for last year a few months ago. Then again, the email says "if you have filed then please ignore this email". Now i dont know if it was received or not and am anxious that it has not been submitted and i will be penalised. Can anyone advise please? Is there anyone from HMRC i can check with? I tried the bot but that was a failured.