Use FD points on AF flights
 

About 6 weeks ago I booked 2 return flights on KLM to JFK from LHR in September using my FD points. I have paid 50000 points(each) and now received 2 economy tickets. I had considered buying economy tickets and using FD points(40000) to upgrade to wbc but cost was too high then(£600). However there are now tickets for sale on Air France for £297. I am now considering cancelling my current booking but have the following questions(which is probably too much for the average FD helpdesk employee) after some research:

1. I paid @£120 in tax for my flights; if I cancel do I lose this money?
2. The AF flights are only available at £297 on Expedia/Ebookers etc not the AF website; does this matter ref. business class upgrade?
3. How can you check whether AF are offering free upgrades on a specific flight before I book the economy tickets?
4. What is the process for using FD points on AF flights; do you call KLM helpdesk or AF?

Any other tips/ things to be aware of?

1. You should be able to get it credited back to your card.
2. No (see 3 below)
3. AFAIK, you cannot upgrade on AF using FD miles
4. KLM

So, 3 is the real killer for you as far as business class travel is concerned.
You may also want to check whether KL fares have decreased and what availability for upgrading those flights is like. If the issue for the high fares is availability, you might want to try EWR as well.

50K for a UK-JFK might perhaps not the best use of miles but this is your call.

Errr hang on it's only 20,000 miles for UK-North America Economy or Upgrade???

Yep.
Economy one-way is 25K
upgrade one-way is 20K

x2 for return.

Hmm FD seem to say it's only 20k for economy then another 20 for the upgrade.

Anyway - still doesn't total 50k :)

Europe-North America in economy is definitely 50K return (or 25K oneway). You can check-in online via MilesFinder on KL sites.

Matt747 stated that they got an economy return to JFK for 50K each.
He had considered, as an alternative, to buy a ticket and upgrade for 40K each (return).

The maths seem to me to work fine.