I am having exactly the same problems with loading the BT SMART talk app onto my i phone 5 mobile. To be honest I am sick to death of being passed from pillar to post in India.
How do I get this fixed, simply and quickly
I finally cracked the system by writing a complaint letter to the BT Customer Service Manger in Durham.
They were extremely helpful and assigned their Smarttalk department to the case, which they fixed today. Since then they called to ensure that the problem had been solved.My Smarttalk app now works pefectly again.