ESA query please.

I won my PIP tribunal 11th August, then got a letter from ESA dated 31st August saying due to recent changes my ESA was changing. The amounts were still on the downgraded rate from when I lost my PIP. So I rang them first thing on the Monday and told them I'd won my PIP tribunal even though I'd already informed them of that the week before.
I have now rung them three times as my ESA has not gone back up and had no letters from them, today when I rang they said yes they are aware of my tribunal win and they can see no reason why I wouldn't be upgraded back up but that it wasn't down to them it's down to a DM, which I knew as they told me this last week also and last week I was told I would know the outcome by last Thursday. No letter so I didn't know what the outcome was, hence my phone call to them today. I was told I would have someone ring me within the hour, that was five hours ago What should I do now please, they seem to me to be stalling and if I am to appeal the 31st August letter time is moving on. I feel they want me to go over this time limit to avoid paying me the back pay.
What do you think is going on please?

All I can suggest is asking your MP to get things moving

Contacting your MP