Google "involuntary bailment".
Thanks @DuncanF
Just to update this thread I contacted Yodel again and apparently they’re coming today to collect the misdelivered parcel and are also going to deliver the dogfood but I don't know if that's the parcel of dog food that's gone missing or the replacement sent from Zooplus.
Curiously when I track the missing pet food parcel and enter the postcode of the other person’s address then it won’t track but if I enter my own postcode it does track and it’s the date and time that the other parcel turned up but if I track the other parcel using my postcode it, again, won’t track but if I put the other postcode in it tracks the parcel and reports that it was delivered four minutes after it was delivered to me so clearly the person who’s parcel is missing has my dog food but according to yodel it’s been reported by someone, me at least, and they’re dealing with it apparently.