[Urgent]Tier 2 refused because of maintenance fund-Reapply

[juanli]

Hi ,

I found this site has been really helpful, would be really appreciated if someone could help me just before Christmas holiday.

I received my refusal letter on 21st-Dec-2016 because of maintenance fund(I have a period 07 Sep - 19 Sep on my account lower than 945 GBP).

My old CoS says employment start date is 01/01/2017.
My police registration and degree certificate is held by home office ( I did not receive them).

I want to reapply, and I have a few questions.
1. Do I need a new CoS to reapply? (My CoS status is used, and it expires in Mar-2017)
2. Do I have to apply before my employment start date?
3. Do I need my documents back to reapply? or can just apply and say my documents are held by home office?
4.If I don't reapply within 14 days after receiving the refusal letter, will I be an overstayer ? which is after 4th Jan 2017?

Any comment is appreciated, have a lovely Xmas!!!!