At Narita airport, when trying to check in luggage, I was told my luggage was overweight. I asked if there were any alternatives (such as sending the luggage in a cargo flight) since they were charging 6000 Yen for every extra kilo (around 70 USD). The woman said there were no alternatives. I told her that I was a frequent flyer of KLM for over 20 years and asked if I could use my miles to reduce the overweight luggage cost. But since I didnt have the card, she refused to check up my card number, even though she was able to. The desk manager then yelled at me that I should pay or step out of line. I had no choice but to pay (with taxes) almost 1700 USD for a single overweight luggage. Incredible.
When I got to my end destination Sweden, I found that the very same luggage I had paid 1700 USD for, was lost. When I received it the next day after it was found, the luggage had been opened, was sloppily taped closed with some duct tape, and the locks had been jammed. I was absolutely furious, when I furthermore found out, that I could have indeed sent the luggage by cargo for a fraction of the overweight luggage cost. I had asked the KLM service woman this very question, and she had said "no there are no alternatives". Perhaps she (being a native Japanese speaker) had misunderstood my question which was in English, but I believe it is the duty of KLM to provide quality English service on all its international flights, so it is no excuse for KLM. I wrote letters of complaint to KLM headquarters along with copies of my original KLM frequent flier card, which proved the abundant number of miles that I had saved from my many years of flights with them (and which should have been able to use for significantly reducing the overweight luggage). I received back a letter dismissing my claim, so I followed with a second letter. The second letter was downright rude and dismissive. It admitted that its employees had delivered poor service, but refused to acknowledge my claims.
I would suggest that KLM spend more time and money on taking a long-term customer seriously (as could clearly be judged by own frequent flyer miles and that of my family who also frequently use KLM services), than primping its ads to attract customers who will take a once in a lifetime splurge flight to Amsterdam for a joy weekend.
I travel long-distance around every 3 months, and I can affirmatively state that I will NEVER EVER use KLM services again, even if it means paying more to another airline for similar services. I will never give a good recommendation for KLM to other customers and I will always make other potential customers aware of the kind of treatment that KLM delivers to its long-term customers.