yes, 3 is the number. They always block the DC when you make 3 transactions in a row.Not much first 2 transactions were less than 50k and third one on which it got blocked was 90k.
usually they'll call you back in 5 mins to confirm if it was a legit transaction. Otherwise you have to wait for them to call and then only DC will be unblocked.
or else, raise an unblock request to customer care.