HMRC Late self assessment Penalty

Hi HMRC, I recently received a Late self assessment Penalty. This wasn't my fault as I have 2 UTR numbers registered to my name and I called HMRC multiple times to cancel the old one - which I was guaranteed was done. This is however not the case since I received a Late self assessment Penalty associated to my OLD UTR number (which was supposedly cancelled). I called multiple times in the past about the issue. Now I have this penalty which I have appealed online. I would also like to point out that I did in fact complete my self-assessment on time and with the correct UTR. My questions are: Do I need to call up again regarding the OLD UTR or will this be taken care of in the appeal since I mentioned it in there? Should I pay the fine even though I am appealing it and I am not in the wrong?

Hi,
If you have already appealed the penalty online, this should be reviewed shortly.
In reviewing the penalty, the issue of your old UTR still being active will also be reviewed and resolved by our Self Assessment team.
If you would like confirmation of the progress of your appeal and the closure of your old UTR, contact us by webchat or phone via
Self Assessment: general enquiries to allow us to access your record.
Thank you.