In reply to mypyrex:
I know that today there was some sort of big re-jig of the faster payments system going on, however it was only meant to apply between 4 and 6 this afternoon. Transactions made then may be cancelled and returned. However as yours was Wednesday it's probably not the case.
Alternatively it's a sneaky tactic banks use to shore up their balance sheets over the weekend, by re establishing uncleared payments temporarily before they miraculously clear early hours Monday morning when the Asian markets open.
None of it is real.