Phoned my house number and when I picked up an automated voice said was it me who purchased a train ticket for £100 from Edinburgh to London as I'd never used my card for this purpose before. They didn't know who had answered their call or who their machine was speaking to - it could have been anyone in our household so how would they know the card belonged to the person answering their call. I put the phone down instead of pressing any of the numbers they asked me to press.