PRO - rather than battle to find out how the money was ringfenced, and whether ASDA could do better, I'd suggest you make a short summary of how things went wrong (acknowledge ASDA did have a staff member come on Tuesday to deliver your order, free, and that by luck - given timescale of 3 to 10 days - the money was returned to your a/c on Wednesday).
I think the main issues are
o how the customer is left in limbo, as the bank cannot reverse the transaction but depends on the merchant (X)
o how systems can be set up which debit the same amount more than once, and the company requesting the funds can 'lose track' or not even acknowledge this may have happened
o how a customer low on cash at the bank (far from uncommon, I expect, eg near the end of a month) can be left with no way to purchase anything (esp if there's no cash withdrawal facility nearby)
Send your summary to Moneybox using e-mail to
[email protected] and see whether they get back to you today or Friday in time for the broadcast on Saturday (or a week on Saturday).
If you don't hear back from them or they appear disinterested, you could try [email protected] (so when Andy Clarke is interviewed in a few weeks, they can query what's being done, perhaps outside the scope of the general 'profiles of supermarket bosses' but no doubt he will want to co-operate or be seen as hostile!)
If you get no joy from either of those programmes then an e-mail to Woman's Hour via their page (since online food shopping, especially where the whole family, including a baby is concerned, may fall on women all across the country) and see if they take on board the frustration you felt with no food and no way to even order the minimum to get through Monday/ Tuesday, with the 25 pound minimum.
(X) This has some similarities to a credit card 'continuous authorisation' where a customer has allowed a merchant to debit a sum (whether monthly, quarterly or annually) for some service (eg car insurance) but the only control over cancelling it is with the merchant.
Changing account number, getting a new card with a new expiry date (and even death) cannot automatically stop the company from taking money.
The customer can ask the bank but the bank will do nothing in most cases. It may be possible to get a refund if one can prove that attempts were made to contact the company to tell them to cancel the service but it's all built to favour the company taking the money, no matter what problems (eg interest, or penalties) the customer may face.