Hey and sorry for the late reply, I am not here on a daily basis anymore.
On the last AGM we discussed with the AGM participants how we deal with defunct members. Heligoland was one of them. We did not receive replies to mails or calls for over 2 years and of course no membership fees. the overall feedback was: "Re-try to get in touch. If they do not want to be a member anymore, expel them. If they want to be a member, but did not react for some reason, try to revive and assist them".
Heligoland is the first team that actually came back, surprisingly. But, not with good news: They currently do not want to be a member anymore as they want to focus on playing occassional German guest clubs instead.
So: We expelled and deleted them, unfortunately.