I am sure you must be assuming that whatever the DP and the broker do is perfect for you. Remember, it is in your hands to ensure utmost safety and security for your demat account. It is always better to regularly cross-check the DP account and confirm. How do you confirm the correctness?
Check your transaction and holding statement on a regular basis. At least twice a month is advisable. Keep an online access, so you do not need to wait for your statement and can highlight red flags immediately. Any discrepancy must be immediately brought to the attention of your DP and you can take correction action. Similarly, insisting that your electronic contract notes be sent to you on a regular basis which you can use to reconcile with your demat statement. There are 3 basic confirmations you must take. Firstly, any shares that you send for dematerialization ensure that the credit is received and reconcile with the DRF acknowledgment. Secondly, when you buy or sell shares in a demat mode in your trading account, ensure that debits happen on T+1 day and the credits to your demat account happen on T+2 day. If that does not happen immediately escalate the matter to your DP and to your broker. Lastly, all corporate actions must be received. In case you find that bonuses, rights, stock splits are not reflecting in your DP account you must immediately escalate to your DP. If you find dividends not credited to your bank account then you must immediately escalate to your registrar. Regularly check the trading account and reconcile your ledger account with your DP account with the help of your contract notes. That is the best safety net available to you.