ESA reassessment date query

I was put in the support group without a medical for 3 years in 2013, I phoned a few months ago to tell them I'd moved house and asked when my next assessment was likely to be, they said it was scheduled for August 2016. It is now nearly August and I've still heard nothing from them, when would I expect to receive an ESA50? If I phone them and ask when I'm likely to hear from them might that make them go "oh no we forgot about him, best send that out soon" or will it make no difference? If it 'reminds' them I may just wait it out but I've been losing sleep for months over the upcoming reassessment and every morning I'm terrified to check the post in case it's there. It's the not knowing that's really breaking me, some idea of a date would at least let me emotionally prepare - I'm on indefinite DLA so I've also got the randomised PIP draw hanging over my head, not knowing either of them is becoming unbearable.

I also checked my old paperwork today and I was told when I received my 2013 award letter I would enter the reassessment pool (whatever that means) on 28th June 2016. I received a letter a couple of weeks ago which was in the standard annual uprate format (the "from X date the rate of some social security benefits may change, you will be paid X amount" letter) except it didn't have that sentence on it (I'd already had that one in April) but curiously it was dated 28th June 2016 - I didn't put the 2 together until now as I'd misremembered and thought the date they gave me was July not June. Has anyone else had such a letter, what does it mean?

Thanks, I phoned them at 8am and the person on the phone said she couldn't see what the change was, said she'd check the length of my award and told me I'm in the support group until August 2018! Perhaps the change was the decision to continue my ESA as my previous date was August 2016 - I had literally never heard of this happening until yesterday. At first I thought I'd heard her wrong but she repeated it a couple of times (probably because I kept making surprised noises), even now I can't quite believe it but my stomach is slowly unknotting.

Is this a new thing? It seems at odds with the usual relentless hounding of benefit claimants but maybe with the massive backlog and delays they don't want to waste the time/money if they reckon the award will be the same. A letter or even a phonecall would be nice though, stop people getting worked up about an assessment that's not going to happen.