Paid for a year - cannot use pro features

I sent this 3 weeks ago as email, never got an answer. I paid for the pro version for one year, but cannot use most of the pro features.

Cannot connect weekplan as a service. When I try and enter the api key provided in weekplan settings, I get an error message (invalid API Login).

Syncs when first connected, but never syncs after that. I need to disconnect and reconnect the calendar to trigger a sync.

Not sure if connected to #2, but showing events on Google calendar shows multiple instances of recurring tasks. Those tasks have not been postponed or ignored, they just keep piling up in GC.

I suspect the problem could be that I signed up with a google account, not through email/password registration. If that's the case, I could register a new account and you could transfer my existing paid subscription to the new one.

If we cannot find a solution, I would like my money back.