Did you ask this before Michael? The question has been asked recently, I don't think any of us knows. I tried a google search which came up with nothing useful. You could contact Thompson & Morgan and ask them.

t&m dont stock them or any of the main seed companys will have to jest keep on trying thanks

I'm not sure those beans actually exist!

i,ev seen them on a tv programe a little while ago but had no luck finding them thanks anyway

I think this is a April Fools joke! Just grow normal dwarf and climbing beans.