I was awarded last Friday and updated UC straight away, they didn't respond to me either. I started messaging on my journal daily and this morning i've finally had a response.
all they said was that my change of circumstances had been completed correctly and that my case is with a specialist team to confirm my sons MRC award. I asked twice about back payment and she kind of ignored that bit, so I will go back and ask again.
So you received your award letter from DLA? i'm waiting for that fingers crossed it arrives today