Update:
Higher tier support has closed my ticket with no solution and the following reason:
It's unfortunate that our system will not allow the change.
I think that this reason is not acceptable, but there is nothing I can do absolut, realy sad!
I thought it might be because they didn't want names with "Lag" in them, but I just searched and found someone named "Lag" so I would hope it's not that.
Google Translate doesn't come up with anything when I enter Dagolag in either (thinking it's something inappropriate in another language, maybe).
It's a mystery to me.
I would guess higher Tier support takes a bit more time @Dagolag, so it might be worth to push them back in this case from time to time (after some days).
I don't see a problem with Dagolag either, so I wonder why it's not possible for you to choose that name. Wish you the best though and hope they can get you the name.
Update:
Higher tier support has closed my ticket with no solution and the following reason:
It's unfortunate that our system will not allow the change.
I think that this reason is not acceptable, but there is nothing I can do absolut, realy sad!