Once we flew from Cardiff to Joburg via Amsterdam with 3 bags. We had paid for the 3rd bag as it contained Xmas presents..all went well to AMS, (it was only a 2 hr stopover anyway)..On arrival late at night in JNB, and waited in vain for 2 of our bags...Yes the one that just had Xmas presents in turned up ok! We asked the KLM rep what had happened, and she consulted a list and told us "Oh your bags got offloaded at AMS, dont worry, they will be here tomorrow!" We were given a little pack containing toiletries and a t shirt, I was lucky, i had a change of clothes in my cabin bag, but my wife had hardly any clothes in hers..so we had to do a quick trip to the shops next day so she could at least have something clean to wear for the last leg of our trip... The bags did turn up 2 days later...and we thought ourselves lucky that we actually saw them again..then 2 trips later, it happened again, at least we both had a change of spare clothes that time! I never flew KLM again..
I have had bags go walkies several times since, but always got them back a day or so later..