National Insurance Refund Interest

I requested a National Insurance refund for a few months from 2022 in January 2023, sending HMRC a letter containing all relevant information. They received this letter on the 9th February 2023. I then received a letter on the 8th February 2024, stating the amount I am owed and prompting me to provide bank information where the money should go. I reply to this letter immediately. HMRC receive this letter on the 28th February and, after calling, confirm they are currently 57 weeks behind on their post (this will likely speed up, but it's not going to go down to like 2 weeks anytime soon). Given it seems I'm probably not going to get the money I should not have been paying from 2022 in 2025, will they pay interest on what is owed? As far as I'm aware, I would be charged interest if I failed to pay national insurance. This money was taken when it shouldn't have been, and is definitely not worth the amount it was at the time, so do they pay any interest or inflation at all (even just a teeny bit like 1%)?

Hi,
HMRC does not pay interest on refunds.
Thank you.

Why not? It will likely have been 2+ years and I would have been charged interest if it was the other way around. That money simply isn't worth the same as it was when it was taken and would have been gathering interest all this time, if it wasn't taken when it shouldn't have been.