Biometric email received but no letter

hi i have misplaced my Indian passport and ilr visa in it and I have changed my name so I submitted my Brp ntl application online for replacing my ilr visa from passport to Brp card with new name.but I have received email from home office says that I will have receive a confirmation letter take it to post office for Biometric fingerprint and documents scanned in 15 days or my application will be rejected but it has been over two months since I have not received any letter yet.
And I have received other email from home office says that if I have previous details of home office record and hasn't received letter then I can still go post office without booking appointment for Biometric fingerprint before application get rejected .
But information services told me that I have to take the letter to book appointment.so please can you please tell me what to do because my deadline date for Biometric fingerprint is 12th may. Other thing I want to know is there is fee to book a appointment showing on my application but I have paid the £20 biometric fee with the application so what is this fee for. Please advise me and explain what should I do next it is very important and urgent I will be appreciated thanks

Biometrics are done at the ukcvas centres and you book an appointment. You don't get a letter in the post to do this.

It isn't at the post office anymore except for a few very minimal visa routes.

When you applied online, you would have been directed to the ukcvas sopra steria system to book a biomteric appointment and upload your supporting documents. The £20 fee you paid is for biometrics at ukcvas and not the post office.

Have you got your new Indian passport?