[dundee] Chip and Pin payments - Consumer Rights when there's an error...

[Rick Moynihan]

For everyone's information.  I have indeed been charged twice...  So
I'll be visiting Tesco's later on... does anyone know if they still do
double the difference on charging mistakes? :-)

On 9 June 2010 14:52, Axel <newsletter at axelbor.de> wrote:
> Hello,
>
> the PIN ACCEPTED just mean that the correct PIN was used. The Terminal
> send the PIN to the card. The card verify the PIN and send a response.
> TRUE  - if the PIN correct.
> FALSE - and a number of attempts remain, before the card is unusable.

Yeah, I knew that the PIN APPROVED message was just between the reader
and the card, but the correct time to display a "TRANSACTION ACCEPTED
- PLEASE REMOVE CARD" is only after the reader is 'sure' that the
transaction is complete.  Being a distributed system there's no way
for it to ever be 100% sure, however this link should be reasonably
tollerant to errors; as it's likely running a reasonably robust
protocol; something like a 2 phase commit would seem sensible.

Including the store in this distributed transaction would be insane;
and as I think has been demonstrated; isn't done in practice....  So
the problem lies in the training Tesco gives to staff, which is that
they err on the side of the store (and their asses) when in doubt...
again reasonable...

What isn't acceptable however is that the members of staff are not
trained in what actually constitutes a transaction... the customer
shouldn't have to care about their systems!  It's analagous to me
paying them cash; if I pay them cash and they accept it; should I be
forced to pay them again if they lose it between their till and my
bank account?  No absolutely not, and that principle should be obvious
and taught to them.

Anyway, I'm sure there wont be a problem with them refunding me... but
it's beyond the point.  People in such jobs need to better understand
where computers are fallible.

R.