Tier4 Student Visa Extension.very Urgent Help Please

[razian97]

hi there,
My brother in law Applied for tier4 general visa extension,he used his Father Bank statement from Pakistan for maintenance funds.he attached affidavit of support from father and NADRA Family Registration certificate to prove relationship with Parents.
His biometrics was taken on 23 September,Today he received a letter from UKBA ,his case worker wrote that NADRA FAMILY REGISTRATION CERTIFICATE is not acceptable form of document to prove relationship with the parents.he asked to send original birth certificate with in 7 days.
NADRA family registration certificate is the same as birth certificate,it shows full name,date of birth,parents name and there date of birth.place of birth ,ID card numbers,address etc etc,issued by Govt.
My Question are,
(1) we have only seven working days to send Birth Certificate,we received letter today on 22 October 2012,date of issue on letter is 18 October 2012,
so from when we should start counting seven working days,from 18 October or from today i.e 22 October.?
(2) It is impossible to get Birth certificate from Pakistan in seven days.can we use print of scanned birth certificate and write a covering letter that original has been despatched by courier service and attach tracking number Receipt ?

I don't know why case worker has asked for birth certificate,why he didn't accept Family certificate,even every other documents confirms date of birth and parents name,like Passport,All educational certificates,IELTS,all college and school certificates.
Please Answer as soon as possible.
Thanks in Advance.