What would you like to know about this please?
Are you prepared to risk being sued?
In that case, just ignore them and wait to see if they issue.
Maybe they will. Maybe they won't. They used not to hardly at all but they are becoming more aggressive now.
If they do sue then you will have to put them to prove but there is no point in engaging in lengthy debates with them now. They will not ever agree with you or conceded their evidence is non existent.
That said, it really doesn't matter whether they sent you proper notifications particularly. The only issue is whether or not they can prove overstaying.
Can I clarify anything for you?
Probably footage of your number place entering and leaving.
I wouldn't put yourself to inconvenience at this stage. They may not issue.
if they do then go and gather evidence of the notice.
They have six years from the date of the wrongful act but you should be sent notification.
If you are not that is a specific ground to set aside judgment.
As long as they have the correct address for you.