I had a Demat account here and about a year back i.e. on 09/10/2014 (My Cust ID - 1482074) I gave a request to close, there was no communication for the whole year and then their was a phone call to pay the yearly charges. I was surpirsed, after digging in I found out that the Closure request was denied due to signature mismatch. I never received any intimation regarding the same. More over their are ways of verification and closing the account. But they did not because they could get the Yearly fees for no reason.