Well the calendar month to respond to your SAR has expired. So I would have expected that you should have received a response by now, even if it was just to inform you that there would be a delay or to ask for further information.
Have you checked your email spam folder?
When you filled in the on-line Subject Access Request form on the 23rd July, did you upload proof of ID and proof of address? For example, a copy of your driving licence and a bank statement or similar?
Do the documents you provided have your correct and current address? And is that the E13 8AY address? And please confirm that you actually live there?
Quite frankly it's very difficult to understand what is going on here.
You submitted representations against the vehicle impound but no response was received.
You submitted a follow up request and no response was received.
You wrote twice (and a third garbled letter) to the London Tribunals and they sent their responses to an address that is six years out of date, even though that is not the correspondence address you provided.
The Tribunal could only have received that address from the Council.
Now you've submitted a Subject Access Request, received an acknowledgement but no response has been received, either by post or email?
On the other hand you have received every statutory document concerning the four other PCNs including the bailiffs Notices of Enforcement, all correctly addressed. Yet there has been no visit from the bailiff to attempt collection of the money claimed. This is also unusual in Newham.
Might there be something else going on that you haven't disclosed?
Anyway you will now have to complain to the Council about the failure to respond to the Subject Access Request.
I also suggest that you write to your local ward Councillors and seek help from them. Whilst the Councillors can't influence the outcome of a PCN, they can help you follow up with your complaint about Newham's failures to respond to your correspondence. I believe you live in the ward of Plaistow West and Canning Town East so try john.morris@newham.gov.uk who is the Deputy Cabinet Member for Highways and Sustainable Transport.
I'll try and write something up for you on Monday.