Trying to upgrade the 2do Free app to 2do Pro via an SMS link and directly from the Store on my phone, an E6, I get the message: "Purchase failed. Tap 'Buy' to try again." I tap 'Buy' and get nowhere.
Yes, I did and am awaiting a response, although the app owner's link is only for problems associated with the app content, etc.
I also had the same problem trying to upgrade Geo Note.
Thanks. It turned out to be a glitch in the system rather than my phone. Store support got it fixed real quick.