paper self-assessment missing

I sent the paper self-assessment form (I am overseas) with a recorded delivery and I can see that it was delivered however HMRC doesn't have the form (I called today). I spent an hour on hold today and the call eventually dropped so don't know what my options are. I don't have a copy of my original form (my mistake), only the proof it was sent. What can I do now? Do I request a new paper form? Last time it took a month to be sent to me. Can I fill in an online form inytead? I don't want to pay a penalty as it was not a mistake on my part.

Hi,

You will need to download and print off the tax return below and resubmit:

Self Assessment tax return forms

If you have evidence the tax return was received by HMRC, you should appeal any late filing penalties.

Thank you.