Also just as a note "Faster Payments" is not always faster.
It can take up to 2 hours with some banks (HSBC, First Direct usually take the full 2 hours) to clear and Santander can take up to 16 hours or the next working day, amongst others.
Especially if it is after the cut off at 5pm... so I wouldnt be too quick to call scammer yet 2 hours havent even passed yet.
I have first hand experience both sending and receiving with bank transfers being delayed up to the end of the next working day.