Shortfalls in NI contributions

I submitted a form on 5th April 2023 to pay back missing NI contributions. July 6 2023 I checked on the progress of this form using the tax.service.gov/uk site and saw that the message "I can expect a reply by 6 September.' It is now 10 October and I have heard nothing. I went back on the tax.service.gov.uk/track site and I see the message "I cannot see my submitted forms'. None of the 3 options given (not all HMRS forms can be tracked...... if you sent a form online it can take a few hour to view...... if you posted a form to us, etc....) are applicable. What am I supposed to do now?

Hi,
Unfortunately, without checking your records we are unable to provide you with an accurate timescale for your application.
Please contact HMRC on 0300 200 3500 ( or +44 191 2037010 if calling from abroad).
Lines are open from 8am to 6pm Monday to Friday.
Alternatively, you can use our webchat facility which is available from 10am to 6pm, Monday to Friday.
Please see the following link:
National Insurance: general enquiries 
Thank you.