This has also happened to me, coming back from LAX in April - now facing a 5 hour wait in LHR... flight booked with Avios and 2-4-1 so I can't use alternatives ex MAN. BA withdrew all direct services from Manchester some years back, insisting that everyone connects via LHR. Now many other airlines have come in, offering much better (often non-stop) options than a connection via LHR.