When your points will be credited after statement generation on 2, how will you be able to redeem them before next statement generation? Whatever points are credited can only be redeemed after next statement. When your pts are getting credited after Aug 2 statement, obviously you will be able to redeem it after Sep 2 statement because that's how things are working with system and it is clearly written.
In some months points got credited on 5th of month. So those having statement date as 4/5 will face problem too. HDFC has never promised that they will credit on 1st itself. No TnC mentions the timeline. It's on them when they credit or more specifically, depends on system. It only says points will credit in following month and redeemable on statement generation.
Now SBI don't even respect the deadline of 2 months for points and for whatever reason delays it by 6 months also. Atleast with HDFC 1-7 is fixed.
You didn't faced it before because points were crediting on 1st of month or by morning or 2nd and when your statement generates at midnight of 2 these points were credited in statement itself.
Ab har month jab points hi 2nd ki evening after 6 PM or 3rd, 4th ya 5th ko aate hai toh bhai kaha se us statement mein add-up honge jo us se pehle hi generate ho chuki hai.
Mail HDFC and get your statement date changed to after 10th of every month say 15th or 18th.