Yeah that's not possible. Your manager 100% would've known about this well into early October. There have been times I forget to clock in, and multiple managers will tell me about it.

Also, what you're saying doesn't make sense on another level which is that if you didn't clock in to start, clocking out for break would've been clocking in. So clocking in would've been clocking out and then back to clocking in again to leave.. Hence, you would've still had punches. Now if you're part time or something, then maybe just tow punches total: clock in & clock out. Which for you would be clock out (with your issue, it would show as clock in without clocking out). So there would've still been some kind of punch made for each shift.

If you're saying that there was not a single punch made at all, that would mean that you never clocked in or clocked out for that entire month.

Lastly, HR would've fired you for job abandonment if you really didn't make any punches for an entire month. This whole thing simply makes no sense. Are you saying that you didn't get paid for an entire month and somehow didn't take notice?? Or that you only got paid partial amounts? I really don't understand what you're hoping to accomplish by this post