A tip maybe.
In one of my Tescoes they have got the salmon 3kg bag away from all the rest and its sitting in the middle of a shelf with anoy=ther brand. Cant think why they have done that but I was on my way to customers services when I noticed it.
Why not asl customer services if they have got it or stock it, if they dont stock it ask for a complaint form. If they stock it but just dont have it, then go for Marks idea and ask for a voucher for one at the offer price.
because I live rurally I have to travel at least 12 miles to a tescoes and that means there are a number surrounding me, all about 12 miles away. I know that peeps who live in towns and such dont think of travelling that far to another branch but if you have other shopping to do as well , it maybe worth it.
You could ring them up first to see if they have it. I want another bag and am hoping to get one on Friday cos the small tescoes about 6 miles away didnt have salmon either!