My game was rejected for the third time!!!!
Same issue, this is the answer of the apple team:
"We still found that your In-App Purchase product/s exhibited one or more bugs, when reviewed on iPad Air running iOS 7.1.2, on both Wi-Fi and cellular networks, which is not in compliance with the App Store Review Guidelines.
We were unable to purchase your more lives IAP. Tapping on the "BUY" button does not function."
They say to me to reproduce the issue....but I can't reproduce it because in sandbox mode all IAP works great!
at this point I wait the solution of the Ludei Team.