I got an ashy Cadbury slab!

I bought they dairy milk with nuts chocolates yesterday around 5pm at Total garage in Standerton and when I tried eating that thing it was so ashy as if it was placed on a dry place this whole time , BB 09/05/2019 so it can't be that it expired. And now they not even answering me on Twitter when I tweeted them the pictures they ghosted me till now. Please help!