PIP Supreme Court Change on Mental Health (Backpay)

Hi there. 

So a few years ago (At least 2019), there was a supreme court ruling that said PIP claimants were being marked incorrectly for their mental health points in the assessment.

I've been getting PIP for 6 years, with 4 since the ruling on the enhanced rate, and I only got the standard rate in the first 2 years (I was one point off, in the mental health section). 

I rang them up back in the day, because they said they would be going back over claims in that period, and look at people who probably should've gotten PIP, or who should've gotten the enhanced rate - and will be awarding backpay based on the ruling. 

So they pulled up my file, and I had been flagged as one of the people to look into, because, by this point, I was on the enhanced rate. The woman on the phone told me it was likely an open-shut case, and I would be given backpay within "the next 3-4 years". 

Anyway, it's been 3-4 years, and I could really use the money nowadays. The PIP waiting times on the phone are insane, and I've never been able to get somebody to help me ring them up and check what's happening with it. 

Does anybody know what's going on with that? Have they forgotten about it or hoped disabled people would be too busy being disabled to bother inquiring? Do I need to sit down and try ringing them again, this time telling whoever's helping me that I'll likely get that money at the end of it? I don't want to miss my chance to get the help.