"Virgin Media certainly do - I sent seven 'return to sender' items back to them that way as they refused to stop sending marketing material - not had any from them for well over two years now....."
This is Eeeevil and I like it, as like you I've been unable to get them to stop even when hitting them with a DPA section 11 notice - the argument they use is that they target the address but not the name, so there's no section11 requirement to comply with.