Sorry to hear that, that is a nightmare !
A lot of stolen cars/vans are moved along the motorway, and the police camera's that go off when they automatically record a stolen plate are pretty good, my neighbour got his motor home nicked and they picked it up 80 miles away on the motorway, I hope they get yours back safe and sound.
If not, I hope the insurance covers/pays for everything soon, good luck.
Did you have anything else in the van like sat nav etc ?