Dell Inspiron 1525 — battery not charging and drained out!!!

my dell inspiron 1525 laptop (service tag: 9C4J1BS ) is just 1 month out of its warranty period.nd 1 day the battery was drained out completely.after that when i tried to charge it, the charge got stagnated to 23% and did not charge beyond it(always showed plugged in, not charging). 2 days ago, it suddenly showed 100% battery, and a few hours after that, the laptop doesnot start without the charger on( the red led dat indicates "no battery" glows!!) its hard to believe that dell, which is soo reputed for the battery life of the computers could provide such cheap batteries which die out within 1 month of the warranty period getting over!!! (there is no problem with the adapter, coz the problem persists even with a different adapter). I am studyin in IIT Kharagpur, but cant afford much-I have obtained loan for the laptop+i have also taken an educational loan. I thought dell would not disappoint me.but it seems i was terribly wrong!!!