I think that might bring on my 'I don't do Tesco' response...

However, I don't think it's Tesco who do the photo processing in Tesco's ; if it's the same business model as Sainsbury's, it'll be an independent franchise operating out of rented supermarket space, which is why the photo processors in Sainsbury's don't take Nectar cards in transactions. I stopped putting films to one of the Sainsbury supermarkets near me when I went back for my one-hour film and saw the guy with a strip of 35mm wedged under the armpit of a big hairy cardigan, and discovered it was my film. My local Boots branch, on the other hand, are very good at film handling, and all staff use white gloves when handling processed materials. Unfortunately they don't do 120 any more, but at least I have a proper local photo shop that does.