The wording on delta's website, says:
"You may check one golf bag with a maximum weight of 50 lbs"
http://www.delta.com/traveling_checkin/ ... /index.jsp
It doesn't say anywhere that golf clubs have to be inside it, that is one reason i want all the bags to still say golf on them...I would dispute the charge on your credit card, it is easier then calling to argue with them...
I have flown several airlines before and opened it up and they didn't care, this was mostly NWA before the merger. Delta must be training the former NWA employees to be as awful as Delta because when I recently flew with my big blue golf bag at 49 lbs, they gave me a hard time about it being a larger than normal golf bag for the first time, but they let me go without any extra fees..
What did they call it? I'm guessing windsurfing equipment or surfboard...At min it should be the same as a snowboard...