First time using GUCs.

On Weds the spouse and I flew AMS to MSP. I had called about a week back to use a few GUCs and was told I was waitlisted but there were 10+ open seats. I called again a few days out and now there were 14 open seats but still wait listed. The I sent a message to DL Assist day before and there were 15+ open seats. I was told they would "clear at the gate".

We checked in and went to the gate desk to ask. The KLM lady said "we don't do upgrades". I was like "um, yes you do". She asked her colleague and she added, "no upgrades!". I was like "are you full in One?". She said if I want to do an upgrade "I have to do it with Delta". I said "well this is a Delta plane an a Delta flight number" to which she jumped in and said "and we are KLM and we don't do upgrades" quite rudely. So how am I supposed to use these??

I called the Diamond desk and was on hold for 45 min while they tried to sort this out. I was told there were 16 empty seats but none for upgrade use. I was like "why"? and they said they were holding them for sale. This was 60 min to departure! I pleaded my case and then they had to go to revenue management to get 2 seats released and then used my upgrades to get us into One. What a pain!

To top it off the KLM agent walked over with my boarding passes and said "you are welcome!". I said "for what?" to which she replied "my generosity!". ...!

Sooo... not sure I am complaining that this was so hard (what did I do wrong?) or complimenting that the Diamond desk went out of their way to get the seats released.

Discuss please!