Go to your messages
At the bottom is a list of catagories
Click subscription POSTS
At the top of the list, click subscription list
That should bring up a list of topics you're subscribed too. Just click the
Subscribed
button to the right of each topic listed
It should change to
Subscribe
When you click it, that should unsubscrube you.
FYI, when you click Subscribe or Subscribed/Unsubscribe there is a slight lag for it to register the change. Its just long enough on my cell to make you think you didnt click it. Just as I go to click it again, it changes and if my finger is close enough, my phone senses it and clicks the button a 2nd time and it re-subscribes me to the topic.
So give it a couple seconds to change..