Kotak Mahindra Bank - Unauthorized account transaction from kotak debit card

Hi,

I had been met into snatching of my bag and in that I lost my ATM card of "Kotak Mahindra Bank" and I took an action to blocked that card then and there however after giving me assurance to blocked my ATM debit card an Unauthorized transaction had been done from my A/C of 18000/- Rs when I called to customer care and also contacted at nearest branch for the same issue then they did not provide me a satisfactory support. They said to me that I should wait for their follow up call for the same issue. I believe it has been a month still there is no such response I have been recieved through any of the concern person from the Bank.
I would like to request to take this issue again into your consideration and please provide me a proper resolution for such incident which has happened into consideration of "Kotak Mahindra Bank" ATM machine at Mayur Vihay pahse -1.