Registered letter to BX9 1AN without a reply

Hello I sent my Application to voluntary contributions as a registered letter from India at 21st March. I have not recieved a reply and also the tracking of the letter shows that the letter is out of delivery at postcode WV11AA. I am not sure if it was delivered. I appreciate any response.

Hi Ivana,
The postcode that you’ve used would appear to be one for The Pension Service.  
If you are over UK State Pension Age you may wish to call the International Pension Centre on +44 191 2187777 and they will check whether they have received your letter.  
You may wish to check the postcode that you’ve used as the one for the International Pension Centre would appear to be WV98 1LW.
If you are under UK State Pension Age then you may wish to complete a new application to pay voluntary National Insurance contributions.  
You can submit your application online by going to Social Security abroad: NI38
Thank you.

Dear Sir or Madam I appreciate your reply. I applied online and I checked when I could expect a reply. It is 11.3.2025. I hope it will be early as I want to pay gaps before 6th of April 2025. Could I do something about it? Yours faithfully 

Name removed admin .

The payments can happen after the deadline. Its important that your application arrives before the deadline.

Hi,
We can advise that you will not be penalised because of the length of time it is taking to provide you with a full reply about any shortfalls of voluntary National Insurance contributions.  
If we reply to you close to or after April 2025 then you will be given extra time to make any payments of voluntary contributions that you wish to.
Thank you.

Dear Jolly G and HMRC Admin 8 I appreciate your replies. I keep the confirmation email that my application was recieved so it should not be a problem. Have a beutiful day