Active subscription, but functions of a free user

I'm paying for the yearly Acrobat Reader Premium subscription, yet the mobile app declares me as a free user. Switching accounts hasn't helped neither. When I click "restore purchases" it tells me that my subscription was cancelled or has expired. And then when I click "Subscribe now" for Premium, it keeps on telling me "Purchase successful. Waiting for feature activation" (without asking for any confirmation), but always end in an error. "Manage subscriptions" takes me to my ACTIVE subscription, but the app still won't allow me to use any premium tools. This has been bugging me for months and I couldn't find any support phone number or mail address anywhere! Might as well stop using it for good at this point.