You can download statements online and that is why registering online is important. Take a print of your demat statement each month and reconcile with your trading account ledger. This can overcome most of the problems that we come across. If you seen any discrepancy bring it to the notice of your DP immediately to get it resolved. There are cases like auctions where y our delivery could get delayed, but you need to get clarity from your DP. Also keep a tab on your opening stock and your closing stock as it is important for your tax filing purposes.