[Resolved]  Dell Inspiron 1545 Laptop — Missing hardware part: inbuilt mic is missing

sir,
i purchased one Dell Inspiron 1545 laptop on 03/04/2009, invoice number is : 00208116 ; service tag numbter is : JPZ33BS,
within few months of purchase i found the internal microphone is not working as well as the external microphone is also in same condition. immediately i contacted customer care of DELL and after so many times of calling atlast they contacted me in the month of September'09. they send one local service engineer but he suggested to change the motherboard, now within the few months of purchase when the product is in the warranty period why should i open the system and assemble a new mother board? i requested the company to replace the whole system. the customer care of DELL agrred with that and they ask for one special permit VAT25 to deliver in SIKKIM, because my working place is Sikkim. somehow i arranged and send the form through courier , but there is no response from there side, whethe the replacemnt process is going on or shall it be done...nothing are intimated from company side, the VAT 25 is validate for one month of issue date. but almost 2 weeks are over but no response i'm getting,
sir i'm a M.Tech student and don't have so much time to spend on this type of harrassing job, please intimet me what shoul i do .