Expiry Date correction in Tier-2 dependant visa

[deiptimtrilokekar]

Hello.
I have a Tier 2 - Dependent visa.
I had applied for a dependent visa based on my husband's Tier 2 which has an expiry date of May 2014; however I was issued with a
visa expiring in March 2013.
I had to urgently reach UK then(2012) hence I did not get my visa corrected back in India.
I applied for a correction in my visa at the UKBA through an agent, but did not get any feedback/acknowledgement from the office. All I have is a Royal Mail confirmation that my passport has reached the Sheffield office. The agent has written back many times asking for status update but so far there has been no response.
I need to urgently get back to India by April, but do not know how to go about getting my passport back.
Please help!