I got redirected by customer support to tech support. I couldn't find any catergory which matched my problem so I took the one that was the closest in my opinion. Here's the issue I sent to customer support.

We are having issues creating a clan. It says for most of us that we already have a pending invitation, but noone can clear it off.
If you would be able to do this manually it would be great.
Clan name: HERMAN-Gaming
Clan tag: HGa
Members: Kuukuna (me), FrauVidgren, kEim0, Dradeth, Wirppa
-Kuukuna