No reply to Individual Carers credit and missing NI and posted at the start of August

I still have not receive any confirmation that either of these letters/supporting documents have been received or processed. I did get through on the phone after holding for a very long time and was told not to worry as I had until April 2025 for the issue to be resolved. I am unclear how long I should wait for a decision since I can no longer make contribution after April 2024.

Hi,
We are sorry but we do not have very much information about your query, but we note that you appear to have sent us a letter at the start of August 2023 and have not yet had a reply.  
If you are asking about paying voluntary National Insurance contributions for any tax year from 2006-2007.
We can confirm that you will have until 5 April 2025 for us to receive your payment.  If you reach State Pension Age before that date then it may be beneficial for you if we receive your payment before then.
If you could speak with our National Insurance Helpline on 0300 200 3500 they will be able to make sure that they have received your letter and give you a date as to when you can expect a reply. 
Thank you.