I take it you don't complain much ash?
Sometimes you have to raise your voice so other customers hear your not happy, im not saying shout and threaten them but managers do not want other people to hear that you are dissatisfied as it is negative.
What's wrong with tesco? i shop at both sainsburys and tesco and i have never had a problem with tesco, if i have to exchange or refund something there has never been an issue, but a supermarket is very different to pc world, you don't take your can of beans back when it has run out and ask for a refill as they should have lasted longer.
Companies also have policies, if the manager is following the policy then their hands are tied whether you are happy or not. you just have to accept it.
You must complain though, i complained a couple of years ago and walked away with a cheque for 6k
