David,
I had the same issue when I bought an rtr kit last year. Durango sorted a new TX set for me with a little bonus gesture for the trouble and were excellent. For the cost the rtr is great value (when working) and served me well to get back into racing. I've since upgraded most things as I got more involved in the hobby (it gets addictive
) but my advise would be to chase through the Durango email and keep your supplier copied in too.
Hope all goes well.