You can only order online as it is a internet exclusive, on the Argos homepage there is a category for online exclusives and in there is the 42pd3000 and the wall bracket. I think the wall bracket is for earlier models as well (the box it turned up in looked like it had been sat on a warehouse shelf for five years

) but it fits the 5000 fine, my hubby just had to nip in the bracket a fraction to get it mounted but that may of just been ours, good luck I hope you get sorted.
Mrs Brethy