My mother, who holds a B2 visa (expiring 2021) was in transit from Johannesburg to Chicago to come see me. Her connection was in Frankfurt Germany. When she it was time to board her flight from Frankfurt to Germany she was told her visa was cancelled and they said they didn't know the reason. A CBP officer called me asking if there could be any reason I could think of that my mother's ticket got cancelled, I told them nothing i could think of. The ran a background check on both me and my mom and nothing came back.
She took the next flight back to Johannesburg, made an appointment for a new visa application and it was approved. The consular said she doesn't know why/when the visa was cancelled.
This was obviously a very expensive trip and I am trying to find out where i can file a claim for all the expenses, if at all possible (travel insurance, airline both failed).
Your input will be appreciated.