[Resolved]  Union Bank Of India — Cheque bounced: signature mismatch

Between January 2, 2009 and February 12, 2009, eight of my cheques were bounced by Union Bank, on the ground of signature mismatch! The cheques were issued to HDFC, Citi Bank, other banks, and all are AC-payee cheques. I have an account with this particular branch o[censored]nion Bank since last 18 years, and this branch happens to be located within our office campus. Never in past my cheques have been returned by this bank because of signature mismatch. On enquiry with the branch manager, I was told that now they have a new cheque clearance system, and they have returned the cheques because they found mismatch with my signature recorded 18 years ago!
I was never informed about this change in system, nor was contacted by the bank regarding the 'mismatch'. They have been clearing my cheques regularly, and all of a sudden, I find myself in an embarrasing situation. Moreover, because I am in UK now, I dont have any control over my money lying in Union Bank because they would not accept my cheques!
And, for every time they returned they cheques, they charged Rs.76/- from my account!