OP, this thread has become a little twisted, can I try and unravel it a little pl.
You don't drive.
A car in which you were a passenger was issued with PCNs(Notices to Driver) on 2 separate occasions recently, in contrast to 'for the 19 years I've lived here I have parked in the same disabled parking space and only displayed my Blue Badge. '.
You have posted 3 PCNs, one of which was on 'my mother's car'.
To be clear:
As far as you are concerned as a resident, there has been a significant change in the enforcement practices at the car park;
You have never held a parking permit for the car park;
You had not received any prior correspondence on this from your landlord or Housing Association;
The drivers are liable however, exceptionally the registered keepers may be held liable instead if the creditor follows prescribed statutory procedure.
So:
Are you the registered keeper of any of the vehicles? Is your mother?
If not you, who?
Is your mother a resident?
Are your/their DVLA details current?