It happened at the old Pit Head Baths of Crown Farm Colliery, Forest Town, where the licencing plates have been removed from the vehicle - the van, however, suffered no other damage.
It happened at some time over the weekend of October 13-15, and the police has been notified.
A spokesman for the charity said: "The number plate NL12 OJP should be attached to the vehicle.
"No doubt it will now be attached to another van, which does not have the decals on its sides and bonnet.
"The police has been informed and the charity is now awaiting the receipt of parking fines and speeding tickets, or something more serious."