You need to keep in mind that you only pay DP charges when you sell the stocks in your Demat account. So, if you trade intraday, there is no delivery of stocks in your demat account. So you do not have to pay DP for selling your intraday positions. Likewise, if you are trading in segments like futures and options you also do not have to pay DP charges, as long as you do not opt for the delivery of shares.