Definition of last day at work.

The company I worked for has made all of its employees redundant. They stated our last day of employment was 31/10/23 and we would receive PILON (3 months notice). We did not receive our final pay until 30/11/2023! I have no interest in working again so asked HMRC about a tax rebate/refund and was told that they would not consider it until 35 days after my employment stopped which HMRC consider to be the day we received the final payment!(30/11) was I technically still employed by my company in November?

[Display name amended - Admin]

Hi jays.pa,
To review your record for a repayment we do need to allow 35 days from the final payment details submitted by your employer, so, if submitted 30 November 2023 it will be 35 days from then. 
Thank you,