After not being able to find any email or conversation with the support I was able to log back in Netflix and get a history of charges to my credit cards, which is still stored in their system.
It looks like it renewed automatically on the 17th every month, and then... it was reactivated on the 20th? I think this lends credibility to the idea that someone on the account tried to watch something 3 days after the subscription ended, couldn't without resubscribing, and simply clicked to restart the subscription. Obviously, it could be as you described it as well.
A simple test would be to see what happens if you try to, today, try to watch something on Netflix. Does it allow you to start watching shows? Or does it ask you to do something like restart a subscription? What do you see today?
After not being able to find any email or conversation with the support I was able to log back in Netflix and get a history of charges to my credit cards, which is still stored in their system.
Dates are in DD/MM/YYYY format
https://victorribeiro.com/netflix.jpg