Information on how to get the NOC has already been provided. I got luck and got the FAX in a few days, from what I have heard it takes anywhere between 7 to 60 days.
His parcel cme via DHL, so there is no point in contacting the GPO, I think.
In case of DHL, the letter will come from DHL, @shahidnaveed23 ask DHL to provide you the letter and the custom letter so you can submit it.
If you have a problem with how 100 rupee is paid, I am not sure I can help you.