No Acknowledgement from Home Office flr fp

I have not received any acknowledgement email either.

I did an online application for FLR (FP) - 03/01/19.
All fees have been paid for and taken out of my account. & I received a payment confirmation immediately on the same day. - 03/01/19
Received my biometric letter online automatically after the application - 03/01/19
Did my biometric the day after at the post office - 04/01/19
Sent my documents the same day with next day special delivery - 04/01/19 (However I misplaced my tracking number) but the post office said it should arrive at the home office the next day before 1pm.

Yet I have not received any acknowledgement email or letter confirming that they've received my application.
Or my documents.

I went back to the post office and they said there's nothing they can do to check without a tracking number.

Others have received an acknowledgement email within 24 hours of making their online application.

It's been over a month now and I haven't received any acknowledgement email from the home office. & I'm very worried.

I called them up 3 weeks ago and they said that they stopped sending acknowledgement letters 2 years ago and that I'm not supposed to receive anything. I know now that this was clearly a lie/false information from the home office because from now reading threads and researching online, other people are receiving acknowledgement letters/emails.

I don't know what to do; I'm very upset and worried! My employer have said there going to terminate my employment if I don't provide an acknowledgement letter by next week.

Please help!! I'm about to lose everything!

When you applied online, you should receive acknowledgment letter/pages along with your Biometric letter. These two letters can be shown to your employer as an evidence of your ongoing visa application. I did this and have got 6 month from my employer. Hope this will help.