unrestricted CoS allocation - time taken by UKBA ?

Hi there,
I was on a Tier 4 Student visa which expired on the 17th of January 2017. I was supposed to leave the same day, however, 4 days prior to the date of expiry I was contacted by a company. I was asked to meet the CEO on a very short notice and my CoS was applied for on the same day (13th of January 2017). My CoS application was made by their legal representative who informed me that he would be applying for my Tier 2 general visa simultaneously as so I could stay back. My Tier 2 general visa application was made on the 17th of January 2017, so effectively I stayed back as per my legal entitlement. Apparently, the applicant is given 15 working days to post all the documents along with the CoS number, and the lawyers are expecting my CoS number to come through before I run out of days to send in my documents. They also told me that there is a helpline to expedite the CoS allocation, but it very hard to get through and that they've been trying to ring them every day. Now, I am worried because I am running out of time. I have been told that in a case where the CoS is not allocated in the next 2 to 3 working days, they would post my documents anyway and attach a covering letter with it asking for more time. I am really worried. Can anybody tell me how long it takes before a CoS number is actually allocated?
Thanks in advance.

My employer applied on 9th Dec for me and we are still waiting for CoS.

We tried to chace with UKVI on phone calls and emails but they doesn't say anything.

They gave a number for the immigration office for us to call however the response on this number was that there was nothing we can do, the case has been allocated to the case working team and can take up to 18 weeks to go through.

The best thing you can do is try ringing the priority service and pay £200 to get it in 5 working days.

Ask your employer to ring on 01415556027 and try your luck.

Got my CoS.

Applied on 9th Dec and recieved today (30th Jan). Contacted UKVI many times via emails and phone to expedite the process.

Thanks all,
mul5387