Aircel — Giving already used recharge voucher

I am customer of aircel i use prepaid connection of aircel.one i bring a recharge coupon of 25 rupees on 1-11-09.when i tried to rechar then i was told that it has already been recharged and contact our customer care exicutive. Then i called customer care exicutive he told that this is already recharged and asked me to go to retaile and said that he will do something. I went to retailer who is in tuglakabad ext. Gali no28 n.delhi. He talked me in such a way that he dont know to whom i have given this coupon to recharge and nothing will happen in this case. I told him that i am ur regular customer i will not do anything wrong for only 25 rupees but he did nothing for my problem.