I think that timing chain TSB was pushed out to 80K miles. If you are over 80K, it does not apply.
If you are under 80K,
If you can find the TSB online, print it out and take it to the dealer. If they still give you static, go to another dealer for the service, and drop Ford an email (they may have 1-800 number too), with all of the dealer info, and tell them about the particular dealer that does not wish to honor Fords Extended Warrenty anymore.
I had to do a similar thing to a VW dealer. I don't know how Ford is about this kind of thing, but VW had the TSB and the dealer taken care of within a couple of days.