H1B premium transfer, receipt awaited even after 11 days

I am in US on H1B from a big name company. I got a new employer, who has applied for my H1B transfer in premium processing. The new employer is a well established, big name US company.

Fedex tracking shows that the documents got delivered on Jan 17th, but even after 11 days, till today (1/27), I have not received even the receipt from USCIS. I had heard that under premium, receipt usually comes within 2-3 days. I see the fedex destination address being that of Laguna Niguel, CA.

Any pointers if this might be an indication of a possible problem somewhere?

you can email the PP dept of USCIS for the status… google for email id.

Thanks! I found the email ids at https://my.uscis.gov/helpcenter/article/can-i-contact-the-service-center-by-email-after-i-file-my-request-for-premium-processing . Will write to them.