I do regular shopping surveys where I get £3.00 for answering questions that take about 20 minutes to complete.
Often I'm asked in a survey, about a product I've never used; if I were to purchase the product how many would I buy for the first time. I then have to place a tick in boxes that are numbered from 1 to 10. I always tick the box indicating I would buy only one. As I've never tried the product before, why would I buy more than one! I often thought who on earth would buy ten without having tried the item, but 'ronnie' you've proved me wrong!
I'm not knocking you 'ronnie', maybe you live some distance from your nearest Asda and you have to take fuel costs into account, so you do a big shop when you do go to the store.
I shop regularly at Asda, and when I've taken things back that has had a problem they've been pretty good about giving a refund.
Trawling the internet, the only quality assurances I can find about Asda is the guarantee they give on their fresh produce, and there's a 100 day guarantee on their clothing.
I think if you don't get any satisfaction from your local store, then write, don't email, to Asda House, Southbank, Great Wilson Street, Leeds. Adress it for the attention of the Chief Executive, Andy Clarke. There's not a hope he will answer it personally, but your letter will end up in the right office.
Good luck.