Duolingo Froze After Section 3 - I Cant Use My One Year Super Subscription

I purchased a one-year Super Duolingo subscription, but after finishing the third section, the app froze and wouldn't progress any further. I've been stuck for quite some time, and despite my efforts, I just can't seem to progress to section four. It keeps asking me to "review" repeatedly, and then it freezes at the same spot. I have wasted a significant amount of time, and it seems I'm not receiving the service I expected. If the technical issue cannot be fixed, I would appreciate a refund for the unused part of my subscription. I believe it's only right that the days I couldn't use the app are restored to my account.