M&S lorries, do not belong to M&S dear boy. Glad your O.k. by the way. They belong to the subcontractor dependent upon which type of merchandise is being hauled, i.e., frozen food is usually hauled by Christian Salvesen, chilled and ambient food is hauled by Gist, a division of B.O.C., and textiles is usually hauled by a division of Salvesen from a different depot to Frozen food ones.
What you should have got as well as the registration was the "BOX NO", this would have identified the supplier depot to M&S.
I suggest you go in person, or write a letter to your nearest store, logical assumption to make that that was where it was delivering, explaining the incident, and your contact and response from the Police. Address it to the Store Manager and make it clear you expect a reply, how it proceeds from there depends, but if you don't receive a reply within an acceptable period I would definetely bang a letter off to their Head Office expressing your dissappointment with their Hauliers and there local Store Manager.
Keep us up to date.