Expiry of LUT

Hi, We have been exporting goods under LUT, however the LUT is going to expire on 2nd April, the documents for renewal of LUT are already submitted with the excise authorities on 26th March, 15. I have the following queries in relation to the same :

1) Is there any stipulated time within which the renewed LUT will be received by us ?

2) What if the renewed LUT document is not received before 2nd April ?

3) Will we have to pay duty on export if renewed LUT is not received before 2nd April ?

4) Can a extension of the existing LUT be requested with the range office or Division office till the renewal of LUT ?

Please reply on urgent basis. Very IMP