A READER called Rosaleen happened across an odd rule on the Tesco online shopping service that she asked us to highlight.

This month, she bought some groceries through the site and paid with her credit card. She spotted an item on the site which was offering a 25 per cent discount on purchases of six bottles of wine, so she bought half a dozen.

The following day the order was delivered and she noticed she had been charged the full price for the wine. The discount had not been applied.

So she rang Tesco – more than once. “Each time I was told that the offer expired on April 10th – therefore I could not avail of it as the goods were delivered on April 11th and the money taken from account on that day.”

In the Tesco online terms and conditions, it says the online price is a guide price based on the prices in-store on the day you are doing your shopping. “However, as we shop for your order on the day you want it delivered, just as though you were shopping yourself, some of the prices may have changed,” the site says.

Rosaleen persisted with her calls and finally received a call from head office last week “offering their sincere apologies for any inconvenience caused”.

“Her explanation was that as I was ordering the wine, a red flag should have appeared warning me that the offer was finishing. I was told that this did not happen, but that the IT department were handling it.

“I am to be sent a voucher for €15 as compensation, but no refund. I am persistent and kept following up. How many have given up?”