"Just Tracked with the bank", that exactly is the problem...With whom exactly you tracked in the bank? I have seen many people in India just walking into a bank and talking with the relationship manager/clerk/customer executive about their foreign currency draft..Now typically, these people are ill-informed about the rules related to a "foreign currency draft"...they just give out information to you, based upon their knowledge of domestic drafts...domestic drafts expire (or as u said, "go stale") in 3 months....however, foreign currency international drafts remain valid for 6 months...Hence your draft has "Not gone stale"....contact the bank again, this time some senior official (preferably the bank manager), explain him the entire situation and ask him to get in touch with the "Nostro Accounts" team of the bank to enquire about the status of your DD....Nostro Accounts teams are typically the team in the banks which take care of international drafts and have full/complete knowledge to help you better...
Hope this helps