I had terrible problems with T-Mobile US international roaming in Japan also. I was able to make calls and recieve calls, however I was not able to use internet

I had terrible problems with T-Mobile US international roaming in Japan also. I was able to make calls and recieve calls, however I was not able to use internet. After basic troubleshooting T-Mobile requested that I call their international support on a 2nd phone and they would happily help me fix the problem with the original mobile phone. Of course I didn't have access to a 2nd phone, I was livid. Cancelled the contract with T-Mobile and got local service. Even in cancelling T-Mobile couldn't get it right, they sent me two additional bills for trivial amounts in the months that followed. Each bill under a dollar.