That's not my flat. That's not my neighbour's flat either, or for that matter any building on my road. As it happens I do recognise it - it's a set of flats on another road with a completely different name a few minutes walk away with a different postcode.
I got in touch with ShopTo's customer service (with almost no waiting!) - they seemed equally puzzled by the whole thing but the best they could suggest was wait and see if DPD redeliver successfully on Monday, or get it sent to a DPD Pickup Shop for tomorrow (which I can achieve without the misdelivered calling card). So pickup tomorrow it is!
Edit: Eurogamer is reporting many fails with DPD deliveries today. Shame, DPD are normally a lot more competent than this.